The Wall Street Journal, Digits Blog, November 30, 2010 by Julia Angwin
http://blogs.wsj.com/digits/2010/11/30/a-new-type-of-tracking-akamais-pixel-free-technology/
Privacy advocates say companies like content-delivery networks and search providers have a lot of data at their fingertips that could be useful in advertising. Akamai “has access to an astonishing amount of Web traffic” and thus could track many users, says Chris Jay Hoofnagle.