"The Interactive Advertising Bureau strongly opposes the scheme by Mozilla to block third-party cookies by default in upcoming releases of its Firefox browser, and we vigorously encourage both the non-profit Mozilla Foundation and its for-profit subsidiary the Mozilla Corporation, which is reconfiguring the Firefox browser, to abandon this proposed change. This move will not put the interest of users first. Nor does it promote transparency or “move the web forward,” as Mozilla claims in its announcement. It will not advance Mozilla’s objective, as stated in its bylaws, of “promoting choice and innovation on the Internet,” but will, instead, impede both. If Mozilla follows through on its plan to block all third-party cookies, the disruption will disenfranchise every single internet user. All of us will lose the freedom to choose our own online experiences; we will lose the opportunity to monitor and protect our privacy; and we will lose the chance to benefit from independent sites like RightWingNews.com LiberalOasis.com, MotherhoodWTF.com, and SuburbanDaddy.com because thousands of small businesses that make up the diversity of content and services online will be forced to close their doors.
He even manges to sneak in a Think-of-the-children argument:
"It is also the third-party cookie that enables urgent messages like AMBER Alerts and weather emergencies to be delivered to relevant, localized audiences."