There's a great op-ed by Stanford's Jonathan Mayer and Princeton's Ed Felten explaining this problem. http://www.slate.com/blogs/future_tense/2013/12/13/nsa_su

There's a great op-ed by Stanford's Jonathan Mayer and Princeton's Ed Felten explaining this problem. http://www.slate.com/blogs/future_tense/2013/12/13/nsa_surveillance_and_third_party_trackers_how_cookies_help_government_spies.html http://www.slate.com/blogs/future_tense/2013/12/13/nsa_surve... Their two labs also wrote a solid academic paper on the topic. http://randomwalker.info/publications/cookie-surveillance-v2.pdf http://randomwalker.info/publications/cookie-surveillance-v2...