Web users have created more than 116 million profiles on MySpace, the social-­networking site owned since 2005 by Rupert Murdoch's News Corp. As I will explain in a moment, many of these profiles are fake. Still, 116 million is more than the number of people in Mexico and the number of cable TV subscribers in the United States.

Parents and members of the U.S. Congress have begun to take note--and they don't like what they see. Conservative groups fomented a media panic this year over the supposed rash of sexual predators on MySpace and pushed a bill through the House of Representatives--the Delete Online Predators Act (DOPA)--that would cut off minors' ability to access this and other social-networking sites from federally funded facilities like schools and libraries.