'Do not track'? Oh what the heck, go ahead

Chalk up another victory for corporate surveillance: Five years after advocates came up with an easy way to let you browse the Web with just a little privacy, the Do Not Track system is in tatters and that pair of boots you looked at online in April is still stalking you from website to website.

With a single browser setting, these advocates thought, users would be able to communicate a preference for their privacy. It would be easier than downloading add-on software or creating a blacklist of specific companies to block. Do Not Track, or DNT, would be the Web's version of the telemarketer Do Not Call list.

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.

Web users who are hopeful about DNT got a small boost in California. State Attorney General Kamala Harris issued guidelines to help companies comply with a new state law requiring them to disclose whether they honor users' DNT requests. But the law doesn't force them to use the system.