Everything you always wanted to know about Web tracking (but were too paranoid to ask)

True or False: Web trackers know nothing about you personally because you're totally anonymous to them.

TRUE and FALSE

Some of the information sent back by tracking cookies includes information that could be used to identify you. As Stanford researcher Jonathan Mayer has pointed out, many sites deliver personally identifiable information (like email addresses) as part of the referring URL sent back to Web trackers. (See "Sex, Drugs, and Internet advertising.") The Web trackers claim that they don't want this information, do not use it, and would not know how to use it even if they wanted to. But if they really wanted to, they could figure out how to use and even monetize that information. It's only a matter of time.

True or False: Federal privacy laws protect our personal surfing data from being used without our permission.

FALSE

There are no laws regarding private collection of your surfing data, though Do Not Track legislation has certainly been a hot topic of conversation lately. Depending on the day of the week and the person asked, the Federal Trade Commission both supports Do Not Track laws and would prefer the online ad industry come up with ways to regulate itself.

Naturally, the online advertising industry prefers the latter option. Companies like Evidon are rolling out an ad labeling program that consumers can use to find out who's tracking them and what kinds of information they collect. Evidon CEO Scott Meyer says only 10 to 15 percent of tracking ads currently carry the labels, but he expects that number to climb significantly by year's end.

True or False: Opting out of tracking ads is an easy one-step process

FALSE

If you really want to become invisible to Web trackers, you've got your work cut out for you. You can opt out of tracking ads from most of the major networks via the Network Advertising Initiative site. But in other cases you'll have to visit the advertising network's site to opt out. And those opt outs are browser and machine specific. If you use multiple browsers or surf the Net using more than one device, you'll have to repeat the process all over again each time.

And -- here's the fun part -- even then many ad networks will continue to collect information about your browsing habits for a variety of reasons, including simply the fact that their cookies already collect this information and they can't be bothered to change them. They'll simply stop sending you ads based on the information they collect.