This morning, Facebook rolled out Places, their location-based service that lets users “check in” to places in the real world. Think Foursquare, Gowalla, et al, but on a much larger scale. Places is only available in the US right now, but still, that’s 131 million users.

Here’s what I find particularly scary about this announcement: Facebook Place Tagging. From Jolie O’Dell at Mashable (emphasis mine):

You can add places, check in to places that already exist, and tag people who are with you. If you’re checking in for a group, make sure you tag your friends before you checkin, yourself. For example, I added my house and checked in there. I then opened the Places page for a nearby sushi restaurant, tagged my boyfriend, and checked us both in there.

Wait a minute! Other people can check me in? Yup. According to Facebook’s FAQ:

You can tag your friends who are with you at any given location as long as you are checked-in and they have set their privacy settings so they can be tagged.

The default settings “for any check-ins are to have them visible only to your Facebook friends.” Facebook’s privacy settings let you opt out of Places sharing completely, but as The Guardian points out, if you don’t opt-out, “you will be asked to agree” the first time a friend tries to check you in.

It’s not hard to imagine how this could become incredibly problematic. Personally, I don’t want anyone but me to have the power to share my location. Remember what happened to Plazes CEO Felix Peterson? Or just consider any number of potentially embarrassing Foursquare check-ins. Now, consider that all of your Facebook friends have the ability to create those awkward location-based snafus for you.

Two predictions:

  • It’s only be a matter of time before we see a blog dedicated to “embarrassing third-party Facebook Place check-ins”
  • The alibi fabrication industry is about to blow right up