By now, we’ve all heard about the launch of Facebook’s newest feature, Facebook Places. Similarly to Foursquare, the new application allows users to check in to locations using their mobile device. Each time a user checks in to a location, it will show up on the local business’s Places Page, as well as in the user’s news feed.

Of course, and as always with Facebook, there are potential privacy issues with this new functionality. Knowing this, Facebook has already built out their privacy settings to allow users to choose who can see their check-in information. The default is set at “friends only” but, like all Facebook settings, it can be customized.

However, one of the functionalities of Facebook Places is to allow users to check their friends into locations, as well as themselves. For instance, Bob and Fred go out for drinks on a Friday night, and Bob checks in to the bar. At the same time, he also checks Fred in, which means all of Fred’s friends now know where he is, and that he isn’t at home. To some, this will be considered a serious privacy issue. I’m sure there will be more to come on this topic as consumers start using the service.

Being one of the few people without a smartphone, I haven’t had a chance to check this out for myself yet. I’m curious what the rate of adoption will be, and what the launch of Facebook Places will mean for Foursquare usage. My guess is that there will be little room for competition now that Facebook is playing in this market, but we’ll have to wait and see how consumers react.