Facebook pissed in the faces of everyone’s privacy again yesterday by activating Places, which allows you and your so-called friends to check-in and announce your location on mobile devices — kinda like Yelp!, Gowalla and Foursquare, but with 500 million onlookers. The company claims it’s not about publicizing your location, it’s about promoting local businesses, socializing, and creating memories to share with your grandkids (awwww!). But it’s also definitely another revenue stream for the company that changes its privacy agreement every week and then lets blogs tell you about it. Yes, there’s overblown alarm about the program’s potential drawbacks, but tell that to a closeted teen, or a lesbian who likes to cheat. Here are five way Places it could make your life hell. And how to avoid them.