An anonymous reader sends this excerpt from ComputerWorld:
"In 2009, a few Internet privacy advocates developed an idea that was supposed to give people a way to tell websites they don't want to be monitored as they move from website to website. The mechanism, which would eventually be built into all the major browsers, was called Do Not Track. ... But today, DNT hangs by a thread, neutered by a failure among stakeholders to reach agreement. Yes, if you turn it on in your browser, it sends a signal in the form of an HTTP header to Web companies' servers. But it probably won't change what data they collect. That's because most websites either don't honor DNT — it's currently a voluntary system — or they interpret it in different ways. Another problem — perhaps the biggest — is that Web companies, ad agencies and the other stakeholders have never reached agreement on what "do not track" really means."