Verizon is altering the web traffic of its customers by inserting a Unique Identifier Header or UIDH, a temporary serial number that lets advertisers identify Verizon users on the web.
According to Jacob Hoffman-Andrews of the Electronic Frontier Foundation, the UIDH serves as a “perma-cookie” that can be read by any web server to “build a profile” of internet habits. …
Verizon has been using Relevant Advertising techniques for two years, but the tracking has gone largely unnoticed until recently, when extra data from Verizon customers was noticed. AT&T appears to be engaging in similar tracking activities, and is testing its own Relevant Advertising system.
How is this legal? Oh. Of course.