Wiping a Smartphone Still Leaves Data Behind 155
KindMind writes "To probably no one's surprise, wiping a smartphone by standard methods doesn't get all the data erased. From an article at Wired: 'Problem is, even if you do everything right, there can still be lots of personal data left behind. Simply restoring a phone to its factory settings won't completely clear it of data. Even if you use the built-in tools to wipe it, when you go to sell your phone on Craigslist you may be selling all sorts of things along with it that are far more valuable — your name, birth date, Social Security number and home address, for example. ... [On a wiped iPhone 3G, mobile forensics specialist Lee Reiber] found a large amount of deleted personal data that he recovered because it had not been overwritten. He was able to find hundreds of phone numbers from a contacts database. Worse, he found a list of nearly every Wi-Fi and cellular access point the phone had ever come across — 68,390 Wi-Fi points and 61,202 cell sites. (This was the same location data tracking that landed Apple in a privacy flap a few years ago, and caused it to change its collection methods.) Even if the phone had never connected to any of the Wi-Fi access points, iOS was still logging them, and Reiber was able to grab them and piece together a trail of where the phone had been turned on.'"
doesn't sound like built in wipe was used (Score:3, Interesting)
Did the previous owner use the "erase all content and settings" feature of that phone? Or just restore it. That would have been using the built in tool and would have overwrote the data. http://support.apple.com/kb/ht2110
A contrived test: old phone, old operating system? (Score:5, Informative)
Did the previous owner use the "erase all content and settings" feature of that phone? Or just restore it. That would have been using the built in tool and would have overwrote the data. http://support.apple.com/kb/ht2110 [apple.com]
The author used the last iPhone (3G) running the last iOS version (4) that would exhibit such behavior. It seems a contrived test.
An upgrade to iOS 5 would fix the problem on the 3G. On newer phones the encryption key needed to access the data is destroyed, so the problem never would have occurred.
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More than just contrived, it is very intellectually dishonest...
Re:A contrived test: old phone, old operating syst (Score:5, Informative)
The author used the last iPhone (3G) running the last iOS version (4) that would exhibit such behavior. It seems a contrived test. An upgrade to iOS 5 would fix the problem on the 3G. On newer phones the encryption key needed to access the data is destroyed, so the problem never would have occurred.
Sorry, but the iPhone 3G tops out at version 4.1.2. The 3GS, on the other hand, does have support for iOS 6, if I remember correctly.
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Yep. I have 6 on my 3GS. The first gen iPad doesn't though.
[John]
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The author used the last iPhone (3G) running the last iOS version (4) that would exhibit such behavior. It seems a contrived test. An upgrade to iOS 5 would fix the problem on the 3G. On newer phones the encryption key needed to access the data is destroyed, so the problem never would have occurred.
Sorry, but the iPhone 3G tops out at version 4.1.2. The 3GS, on the other hand, does have support for iOS 6, if I remember correctly.
My bad. I might have been thinking of the iPod 3rd gen which tops out at 5.1. The iPhone 3GS (also 3rd gen) is supported by iOS 6.1, the current version.
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Load the 3G with music ... (Score:3)
There is an app for that ... (Score:5, Interesting)
After erasing the contents fill the 3G with music to overwrite, then erase again?
Pretty sure the filesystem in iOS can have partially empty blocks. I'd make a copy of my music, then run find . -type f -print0 | perl -n0e 'truncate($_, -s $_ >> 13 13)' to make sure that all the files were rounded off to 4096 bytes first.
I just thought to check for apps that wipe storage, there are several. I should have known there was an app for that. :-)
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Both iPhone & Android phones less than 3 years (Score:2)
But you're assuming that everyone who had an older phone ran out and ditched it the moment the new ones came out and thus there are no older iPhones with older software in use.
Oh wait... we're talking about Apple. Ok, yeah, everyone DID immediately ditch their old phone the moment the new model came out. Nevermind.
Its been nearly 3 years since the 3G has been sold. Both iPhone and Android users tend to have phones less than 3 years old.
So? (Score:4, Insightful)
This was to prove that selling your OLD PHONE can raise security issues
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This was to prove that selling your OLD PHONE can raise security issues
It still seems contrived, the 3G is obsolete not simply old. To avoid redundant posts: http://slashdot.org/comments.pl?sid=3607997&cid=43344171 [slashdot.org]
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It was also a iphone 3, the 3G and newer all solved this problem. The Article is horribly out of date.
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Or the wi-fi access point MAC address was duplicated by some cheap SE Asian company?
I'd say there is a higher probability the location data was just wrong.
Its obsolete, not simply old (Score:2)
The author used the last iPhone (3G) running the last iOS version (4) that would exhibit such behavior. It seems a contrived test.
It's only contrived if you fail to consider that most people who are SELLING a USED iPhone on Craigslist are selling their OLD model, not the new one they just purchased.
The 3G is not simply an old model, its an obsolete model. Many actively supported apps won't support its CPU (armv6), amount of RAM (128MB), or OS version (4.2.1). The 3G was replaced by the 3GS nearly 4 years ago, it sales slowed before that due to the impending release of the 3GS, and it has not even been offered as a low end budget alternative for nearly 3 years. I expect the used iPhones being sold today are generally iPhone 3GS or 4, phones that are supported by the current version of iOS and actively
Re:doesn't sound like built in wipe was used (Score:5, Funny)
Quick, someone tell 2008 that they have a problem with phone security.
Tried to call (Score:5, Funny)
Quick, someone tell 2008 that they have a problem with phone security.
I tried to call the iPhone owners but they were all on AT&T and had no reception.
Then I tried to call all the Android owners but their batteries were all dead...
Re:Tried to call (Score:4, Funny)
Re:doesn't sound like built in wipe was used (Score:5, Informative)
When you do read TFA you find out this:
Take the two Motorola devices(android). Both were wiped, and neither had much to speak of stored in their built-in memory, just some application data with no personally identifiable fingerprints.
But one user left his micro SD card in the phone. Although the contents of the card were deleted, the card had not been formatted. This, apparently, meant the files were recoverable. And because Android cached application data to this SD card, Reiber could recover e-mail data as well — enough that we could positively identify the phone’s owner via his e-mail address. But the real treasure trove was the photos and documents. The photos still had metadata, including the dates, times and locations in which the photos were shot. And while the documents were benign, if the phone’s owner had stored sensitive information on his phone — think a tax return with a Social Security number, or a .pdf bank statement — we would have had that, too.
So other than USER Stupidity of leaving his SD card in the device he recycled, this once again is an Apple story pinned to a model long out of production dating to a problem long since fixed by Apple.
Not that it changes much, if the police who buy these forensic tools happen to get your phone they pretty much have everything they need to know everything about you. How does "AccessData" get around violations of the DMCA by building tools to circumvent encryption?
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No encryption is being circumvented. Data was simply read directly from a device. To violate the DMCA you firstly have to be in the USA, secondly it has to actually be encrypted in the first place, and that encryption must be reasonable too. Reading deleted files doesn't count. You don't get in trouble for running a deleted files recovery tool.
Also, the quote you pasted has nothing to do with Apple either, the stupid user problem leaving their SD card in it was for Android. Apple failed by not overwriting t
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Many new android phones automaticly use the SD card for everything, apps, phone data, etc... which is by far the best move there is, and why built in phone storage is worthless.
store everything on the microSD card, and when you End of Life, either physically destroy, or gutmann wipe it, or both, from a smart card reader, attached to your PC.
Phone is clear.
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But you miss the point here, and as a result you got it exactly backwards.
The phones all handle wipe of internal storage just fine, but virtually none of the phones wipe microSD cards. MicroSd is a security nightmare.
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My phone also supports SD card encryption but I haven't bothered. I bet that would have thrown a monkey wrench into his recovery process.
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Lets see you take that out and destroy it (via remote wipe) after you lost your phone, or when the arresting officer confiscates your phone.
In fact in virtually ANY situation (other than recycling the device) that you would want to wipe your phone you can't wipe the SD card.
So yes, add-in Microsd cards are a security mess, which is why Google no longer recommends them, and Apple never did.
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No seriously, they were reviewing apps for doing your taxes on the news this morning, take a picture of your w2 and it imports everything. Probably does the OCS on an unsecure channel back to turbotax.
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unfortunately it doesn't work reliability across all models, vendors, and there is no real good guide on which models really work.
Oh, and you could get a kernel panic if using a kernel older than 3.0 or 3.2, or your drive doesn't work right.
# hdparm --security-erase
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There are companies that do secure physical destruction of drives or physical components. as far as shooting HDDs go, its fun, but it still doesn't assure all data is irrecoverable. the
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I'm seriously asking, because I can't figure it out...
Depends on the phone and the methods used (Score:5, Informative)
Most decent cell phones have built-in encryption which wipes the phone by simply deleting the built-in keys. Some cheap-ass droids and the 'feature-phones' may not have it built-in but it's fairly easy to wipe a phone that has the feature.
Off course, if you use the wrong methods (such as simply 'restoring' the phone) or using unencrypted external media, not much is going to help you. If you really need to get rid of your data (eg. in an enterprise environment) I would hope those in charge of the devices would know how to configure and manage the phones correctly so they can be remotely wiped etc
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The bad news is that only since Android 4.0 that there has been decent encryption in devices. Before that, only some Motorola devices had some ability to encrypt the SD card and the main filesystems.
The good news is that Android has grown up, and uses dmcrypt to encrypt the /data partition. One can even have the passphrase that decrypts the filesystem separate from the screen unlocking PIN, using a command line and the vdc cryptfs changepw command. This way, if the device falls into the wrong hands and g
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If you are reselling the device just remove the SD card, or stick it in a PC and use DD to write /dev/urandom to it. Obviously some users will find the latter approach too technical, or not trust SD cards enough, so selling it without an SD card is a fine solution.
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that just takes care of the sdcard though and leaves the internal rom untouched. wiping that is a possibility too though.
doesn't sound like the phone in the article was wiped at all though.
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Phones with no encryption could just "dd if=/dev/zero of=/dev/mmcblk0" or equivalent. It's just a matter of user-ignorance, not of software issues.
This is old news, and no longer correct for iPhone (Score:5, Informative)
The key line: "On a wiped iPhone 3G"
Starting with the iPhone3GS, iOS encrypts everything with a random AES256 key. When you say to wipe the device, it erases that key rendering everything else unusable. This is mentioned in the article, but downplayed. It's been a long time since you could even buy an iPhone 3G, so it seems alarmist to bring it up now.
http://blog.itsecurityexpert.co.uk/2011/10/securely-wiping-your-personal-data-from.html [itsecurityexpert.co.uk]
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How many times are you going to quote that article without understanding WTF you're quoting? And you call yourself a CEH?
Jesus Christ.
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I'm actually impressed. Good for you.
Who the hell keeps their Social Security number (Score:2)
on their phone??
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For real.
I get why that could be a problem with a PC. After all, it's not unusual to file one's taxes on one's PC, or have other records that might include one's SSN on a PC. But who the hell is doing anything like via a phone?
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TurboTax and other have products that work on smartphones and tablets. I do not believe they save anything like that locally though.
Newer phones (Score:4, Interesting)
Sigh... (Score:2)
we rounded up every old phone we could scrounge up from around the office and asked the owners to wipe them. Our stash consisted of two iPhone 3G models, two Motorola Droids, an LG Dare and an LG Optimus.
There were similar discrepancies in what Reiber found on the two iPhones, although both were 3G models running iOS 4
It’s worth noting that the iPhone 3GS and newer versions use a hardware encryption key which is deleted when the phone is wiped, but data was easily recovered from these older models.
Oh no! Five-year-old* long-discontinued phones running old OSes lack security! The horror!
* okay, the Droid is only 4 years old, and the Optimus a mere 3. (And both shipped with Android 2.0 or earlier.)
Can we please be more specific? (Score:2)
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Or maybe it reflects the fact that few people still use them, and nearly no one would if they had a choice.
Most modern smartphones support good encryption. Just use that.
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No my argument is that the LG dare might have been more popular than any single Blackberry at one time.
Sentence doesn't make sense! (Score:2)
While referring to getting all data erased.
'Problem is, even if you do everything right, there can still be lots of personal data left behind.
Wouldn't that mean you just didn't do everything right? Huh?
Google doesn't help matters by providing no avenue for de-linking one's no-longer-owned device from an existing [Google Play] account. Sad.
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I guess I didn't make myself clear...Let me rephrase:
If you destroy your 1st Android phone and obtain a second one, there's no way of removing any reference to the 1st phone from Google Play. Or is there? I have 7 devices listed, six of which I no longer own. How do I prevent them (the six I no longer use), from getting listed on Google Play? Got it?
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Vague useless article. (Score:4, Informative)
The article makes no mention of WHICH Android revision each of the given phones tested was using.
It was a known problem with Gingerbread and earlier that the wipe method used by most Android devices was insufficient. That's why Google added secure erase prior to reformat with ICS (maybe HC too, not sure...)
https://android.googlesource.com/platform/system/extras/+/c2470654d4b4db09a7052fc5fa108ac21f1b1948 [googlesource.com]
Interesting result of this: Samsung's eMMC chips that were shipped in the Galaxy S II and original Galaxy Note couldn't handle this secure erase command properly, and using a standard "secure" wipe had a pretty good chance of corrupting the wear leveller so badly the chip would be rendered useless. (Samsung's own recoveries were "neutered" so as not to issue a secure erase command.)
TL;DR - Unless crippled by the manufacturer, any recent Android device (ICS or newer) should not have any of the issues with data remaining easily recoverable after a wipe described by this article. LG didn't do anything special here - they just implemented ICS or later and that's all that was needed.
SO what do you need to be sure? (Score:2)
Van der Graaf Generator?
Oxy-acetylene torch?
Cement kiln?
I know what to do with a hard drive (DBAN followed by drill press) and a DVD (shredder).
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Nuke it from orbit. It's the only way to be sure.
Putting the article asside for a moment... (Score:2)
How the hell on EARTH do you have "61,202 cell sites" without de-duping?
Then I checked the US wireless quick facts and found:
June-12 June-07 June-02 June-97
285,561 210,360 131,350 38,650
Yikes, that's quite the expansion... but regardless, it still means this phone would've travelled through a very large number of dense American cities to get up to that count.
theres only one way to wipe discarded hardware (Score:2)
So don't sell it but (Score:2)
Sigh. Again, for real security, get a blackberry (Score:2, Informative)
Once again, blackberries solved this problem about 10 years ago (or more).
If you want real, audited, certified security, get a blackberry.
If security isn't important to you, android & iphone are fine.
Sadly, most people are in the latter category.
Best wiping solution (Score:3)
"Will it blend?"
Re:Can't hide it (Score:5, Informative)
With iOS it certainly isn't. Note the iPhones used in the article were deliberately selected to be very old. iPhone 3G.
With newer iPhones, every single byte is written using a hardware based encryption key. AES-256. Wiping the phone involves deleting just the key. At that stage none of the phone's data is recoverable. Not by anyone.
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How exactly do you fight back against AES?
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Only if you are so stupid that your PIN is only 4 numbers and you allow unlimited retires. I am pretty sure iOS now makes the retry interval longer and longer to avoid this attack.
They just brute force it, that is not anything special.
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And did not reset the phone. you cant brute for a pin when the key is completely deleted.
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Retry interval and retry count are irrelevant if you just read the data directly from the flash chip. That's one interface in the iPhone that is completely open and standards based.
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If you have it set, the device PIN unlocks the AES key that decrypts the phone's filesystem.
If you allow unlimited guesses at the PIN, you can unlock the AES key and decrypt the filesystem.
If you erase the phone (reset all content and settings) the phone securely wipes it's AES key - the filesystem is from that point forwards nothing more than random data. If you have an attack against AES256 then you stand a chance at recovering something, but you don't...
There's no use in guessing the PIN as the encryptio
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Do you even understand what you just cited? That has *NOTHING* to do with an iPhone 3GS and onwards that was wiped.
Once wiped, it is not recoverable. The key is gone. Please learn and understand your tools and limitations.
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Barring a weakness in the key generator; iirc that was how the PS3 was cracked?
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Weakness in a key, and the key being *GONE* are two different things.
One can be hacked. The other is irreversibly *GONE*
You really should go read up on how public key crypto works.
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It's not *GONE* if you can regenerate it.
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And I can be filthy rich if I can win the powerball.
Show me how you regenerate a deleted key.
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That is 100% false. Any "digital Forensics" person claiming that is a big far liar that has no clue at all to how it works or how even computers work.
If someone you know told you that, you need to have them show you proof.
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Re:68,000 wifi points?? (Score:4, Informative)
Some napkin math, assuming he purchased the phone in July 2008 when 3G went on sale, and it's been in use constantly for the last 57 months ... and ball-parking 30 days/month ... he hit 40 Wi-Fi points and 36 cell towers every day.
Even with the assumption that these are not unique access points (i.e. his home WiFi is counted 3 or 4 times a day, depending on how often he comes and goes) ... that's still an insane number. If we change the time-frame to 2 years, roughly the average lifespan between upgrades, he's up to 95 WiFi points per day.
Quite the busy bee.
Re:68,000 wifi points?? (Score:4, Insightful)
Even with the assumption that these are not unique access points ... that's still an insane number. If we change the time-frame to 2 years, roughly the average lifespan between upgrades, he's up to 95 WiFi points per day.
If the wifi points are non-unique, 100 wifi points per day would be downright easy to achieve. I probably pass far more than that on the way to and from work each day on the bus.
Remember, it's not "how many networks have you connected to" but "how many have come in range of your antenna."
Unique points would be a lot harder to hit, but as someone else points out, you could probably rack up access points very quickly in a metropolitan area.
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Some napkin math, assuming he purchased the phone in July 2008 when 3G went on sale, and it's been in use constantly for the last 57 months ... and ball-parking 30 days/month ... he hit 40 Wi-Fi points and 36 cell towers every day.
Not that difficult. Just sitting at my desk, my Galaxy S3 picks up 36 Wi-Fi networks. I probably walk past that many again on my way to work. And a few dozen more any time I walk into an apartment building.
I consider it rather mystical how any Wi-Fi network is able to function at all with this amount of crowding in the channels.
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Either you work in a very very crowded area, or San Diego is seriously slacking in the Wireless department.
There are exactly zero visible wireless signal available from my office. My company's SSID is not broadcast, and it's a fairly large campus, so no others can make the trip in. From my home, I can see a few, maybe 3 or 4 on a good day (including my own.) Perhaps people in my neighborhood just keep their SSIDs hidden.
Some more napkin math time! Assuming you're on flat ground (because it's been a LO
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Either you work in a very very crowded area, or San Diego is seriously slacking in the Wireless department
And giving each WAP an average range of 100 feet to your phone
Downtown core in a city of 200k.
My number is probably inflated a bit given that my desk is ~80m off the ground and next to a window. According to opensignal's DB, some of the networks I'm detecting are 1000+ feet away.
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If anyone knows a way -- either on Linux or Windows 7 -- to record a list of SSIDs which are visible over time, I'll run it on my bus ride and see how many unique networks are visible during the entire route.
InSSIDer [metageek.net] might be what you're looking for. Also available for Android and Mac.
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If anyone knows a way -- either on Linux or Windows 7 -- to record a list of SSIDs which are visible over time, I'll run it on my bus ride and see how many unique networks are visible during the entire route.
I'd actually be interested in this as well. Hopefully there's a tool that doesn't require a "Smartphone forensics" degree. I only see a few networks whenever I look ... but that doesn't mean I'm not passing through the range of many more. I intentionally set my phone to *NOT* pop up and ask me about every stinkin' wireless network it sees. Joins the ones I know, ignores the rest, and
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I see 11 access points sitting at home, in a chunky brick building. If I take the metro into central London I go past 10 access points just underground (in the stations, and that's only the public ones).
Heading straight home gives another 10 + 11, so that's already over your average.
(My own router's signal doesn't reach from one end of the flat to the other, due to the chunky walls, and most of the 11 signals I see are very weak, so I probably hit 5-10 see-you see-you-nots just going to the kitchen and bac
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Or he rides the train. In addition to the fleeting contacts from outside, there's people tethering on the train.
It's still quite a lot, but I suppose it's vaguely possible.
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Since I got an OG Droid in November of 2009, I've purposefully observed 132,205 non-unique access points just in the course of normal short traveling for work and pleasure, exclusively by car.
I am unsurprised by any of these figures.
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Ah, NON-unique. Yes, it's not at all surprising then.
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And 93,077 unique access points, over the same period.
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Next question?
Email, of course (Score:2)
It could have been in an email:
* State/gov authorities.
* Insurance company.
* Your doctor
* Digital copy of payslip
etc.
Do you not have access to your email via your phone?
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It could have been in an email:
* State/gov authorities.
* Insurance company.
* Your doctor
* Digital copy of payslip
etc.
Do you not have access to your email via your phone?
Umm...if any company that I dealt with actually did this, I would be severing all relationships with them immediately and demanding that they remove my information from any and all databanks they use. They may actually have my SIN, as provided by me in person or via sealed snail mail when I contracted for their services, but that information should never, I repeat never be treated so casually.
No, I do not send or receive sensitive personal information such as my SIN via email. Nor do I scribble it in the
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"They may actually have my SIN, as provided by me in person"
Hello fellow shadowrunner... is that a Corporate SIN or is it your fake SIN for your missions?
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"They may actually have my SIN, as provided by me in person"
Hello fellow shadowrunner... is that a Corporate SIN or is it your fake SIN for your missions?
Ah, right, yanks call it a SSN, not a SIN...us canucks are all SINners, at least once we're old enough to work... :)
Re:Email, of course (Score:4, Insightful)
In the 26 years I have had email and 12+ years I have had a smartphone I have never, EVER sent or received an email with my social security number in it.
This fear is a Capitol F in FUD.
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How girly... I use a 50BMG round and a binary explosive behind it.