Yesterday Facebook launched its new check-in service, Facebook Places. Walt Mossberg may have called its privacy controls "mostly logical" but here's one that isn't. The service not only allows you to alert all of your "friends" of your whereabouts, but it also lets your friends tag you when checking into places. As Gizmodo points out, you might want to turn this feature off, for a variety of reasons:

You are at the bar when you are supposed to be at your girlfriend's crappy art show. Your chat with your friend Jane, who checks into the bar and tags you: "At this awesome bar, just talked to [Your name here] about his Star Wars memorabilia collection!" Your girlfriend sees this on Jane's wall, walks over to the bar and dumps you on the spot.

You are having an affair with your wife's sister. Your wife's sister checks into her home and says "Having awesome sex with [Your name here]". Your wife sees this on her sister's wall and divorces you. (Also, a robber you're friends with steals your Star Wars memorabilia collection because he knows you're out having the affair.)

Read the complete step-by-step guide on how to avoid these -- and more prosaic sticky social -- situations, at Gizmodo.