Facebook announced a new feature this week called Nearby Friends that will allow you to see which of your friends are near you in real life. The feature can also share your exact location to others. The app uses geolocation technology within mobile devices to determine your proximity to your Facebook friends.

Facebook already allows users to “check in” and post their location on Facebook, though this new feature will take it to another level, broadcasting the location of the feature’s users without them posting anything at all.

Facebook says that it is aware of the potential privacy violations of this feature, and have thus made it opt-in-only for users. In other words, mobile users don’t need to have the feature if they don’t want it. However, Facebook is set to begin heavily promoting the product, posting promotions for it in users’ News Feeds and frequent reminders that the product is available, according to Mashable. It’s also important to note that once the feature is turned on it will not automatically turn off. While Facebook says it will issue periodic reminders to users to turn it off, many potential issues could arise if users leave the service running all the time. While it will certainly be helpful in situations like trying to find friends waiting in a bar or nearby restaurant, the feature could stir up its fair share of privacy problems, too.

Users choosing to opt-in to this feature should carefully go through their friends list first. It’s not the best idea to broadcast your location to casual acquaintances or people you don’t know personally.