Police in Madison, Wis., have been using Facebook to track student parties since Halloween--and they will continue to do so in 2007. So might police in other states: The Madison cops tell the University of Wisconsin-Madison Daily Cardinal counterparts in Milwaukee and Nevada have called them to learn more about their techniques. Echoing the generational divide on ideas about privacy, Wisconsin students told the Daily Cardinal they didn't like police invading their lives, while a professor who studies Internet privacy said that was "naive." "Facebook is like walking down State Street naked," she says. "You wouldn't walk down State Street naked, right?"