The danger [of location based services like FourSquare] is publicly telling people where you are. This is because it leaves one place you’re definitely not… home. So here we are; on one end we’re leaving lights on when we’re going on a holiday, and on the other we’re telling everybody on the internet we’re not home. It gets even worse if you have “friends” who want to colonize your house. That means they have to enter your address, to tell everyone where they are. Your address.. on the internet.. Now you know what to do when people reach for their phone as soon as they enter your home. That’s right, slap them across the face.