I think it's only really a problem if you're constantly posting where you are in a way that lets people know when you are out, how long you'll be out, and how much time they have to rob you.
Yeah. Foursquare is pretty retarded to use, in my opinion.
Otherwise, I like it. I like to know the tiny details of people's lives. It's flavorful.
I love the age of blogging and twitter. It's really helped out my business.