Ask Slashdot: Datacenter HDD Wipe Policy?

New submitter socheres (1771002) writes I keep a Slackware server hosted at various datacenters on leased hardware for personal / freelance business use. I have been doing this for the last 10 years and during this time I moved my stuff to several datacenters, some small and some big name companies. No matter the hosting company, since I choose to install my own OS and not take a pre-installed machine, I always got the hardware delivered with the previous guys' data stored on the hard drives. It was also the case with spare drives, which were not installed new if I did not ask specifically for new ones. Has this happened to you? How often?