By now you may have heard of Max Schrems, the Austrian law student and privacy gadfly who got a lot more than he asked for when he requested that Facebook turn over all of the data it had collected on him. To his surprise, Facebook gave him a file that was 1,222 pages long, filled with detail of things he had posted, searched for and said, many of which he no longer remembered.\n\tMaybe Schrems is an outlier, someone who spends inordinate amounts of time online. Even so, his experience highlights something we need to come to terms with: the vast amount of personal data we are giving to online giants like Facebook and Google, and thousands of much smaller companies you never heard of that are tracking your every move on the Web. What brings this to mind is Google's bizarre offer to give users $5 a month in return for the privilege of adding an extension to their Chrome browsers, called Screenwise, that will record every site they visit and what they did there.\n\tI don't like to use the word stupid; it's insulting, judgmental and often wrong. In this case, however, I will. You've got to be stupid to do this. It's not that Google will deliberately do something terrible with the data it pays you to divulge. The issue is the dangerous lack of privacy that every single U.S.-based user of the Internet is already faced with. Making it easier for Google -- the company says it wants to give users a better experience on the Web -- to find out even more about you, is simply not in your own interest.\u00a0 \u00a0\n\tLori Andrews, a Chicago-Kent College of law professor who has written extensively about social networks and privacy, explained that very well in an essay she wrote for the New York Times.\n\t"Material mined online has been used against people battling for child custody or defending themselves in criminal cases. LexisNexis has a product called Accurint for Law Enforcement, which gives government agents information about what people do on social networks. The Internal Revenue Service searches Facebook and MySpace for evidence of tax evaders\u2019 income and whereabouts, and United States Citizenship and Immigration Services has been known to scrutinize photos and posts to confirm family relationships or weed out sham marriages. Employers sometimes decide whether to hire people based on their online profiles, with one study indicating that 70 percent of recruiters and human resource professionals in the United States have rejected candidates based on data found online."\n\tGet the picture? It's not just that annoying ads and popups based on your recent activity on the Web will follow you around. Various companies, governmental agencies and snoops of all varieties can and probably will make use of your data for their purposes, whether you like or not.\n\tI'm a heavy Web user, and like many of you I utilize Google, Twitter and Facebook for my job and my personal life. I don't hate those companies; indeed I admire much about them. However, they are in business to make money, and as Lori Andrews points out, they don't sell widgets, they sell data. Your data.\n\tUltimately, they have no real incentive to protect your privacy. Facebook is probably the worst offender, and what's so maddening about that company is its constant cycle of privacy violations, followed by abject apologies, which are then followed by new privacy violations and new apologies. And now, Facebook is on the verge of a $75 billion IPO that will make CEO Mark Zuckerberg one of the richest men in the world, and create many, many insufferable young millionaires, all of whom will be getting rich on your data.\n\tGoogle's business is different than Facebook's in many respects, of course, but at bottom it is also about selling ads based on what it knows about you. So given all of the potential problems that a loss of privacy represents, why on earth would you give up even more for a paltry $5?\n\tThere's a big push in Europe to give users more control over the use and collection of personal data. It's about time that Web users in the United States do the same.