“That relative anonymity of the “old days” is now effectively gone. Everywhere you go on the Internet, the fact that IP address xxx.xxx.xxx.xxx went there is recorded. Everywhere you go where you’ve allowed a cookie to be deposited, the fact that the machine carrying that cookie went there is recorded—as well as all the data associated with that cookie. They know you from your mouse droppings. And as businesses and advertisers work more closely together, the span of data that can be aggregated about you becomes endless. Consider a hypothetical that is completely technically possible under the existing architectures of the Net.
You go to a web page of a company you trust, and you give that company every bit of your private data—your name, address, social security number, favorite magazines and TV shows, etc. That company gives you a cookie. You then go to another site, one you don’t trust. You decide not to give that site any personal data. But there’s no way for you to know whether these companies are cooperating about the data they collect.”
(Lessig on Privacy)
In his book titled Code v2, Lessig dedicated a chapter to discuss about ‘privacy’. He provided comprehensive explanation on privacy issue, from the user activity perspective to legal debates. He offered some solution as well.
You can download Code v2 using the link above.