At times, Facebook is surprisingly good at figuring out who you "should" be friends with on the social network. People whom you have a lot of mutual friends in common with; people you've recently been tagged in photos with. While not 100% accurate, these factors certainly make sense in helping you find pals you haven't yet friended.But apparently Facebook takes other factors into account, as well — and that can lead to some intensely creepy (if not downright unsafe) situations.Fusion uncovered the latest example of this. A psychiatrist noticed that Facebook had started recommending her own, mostly elderly, patients as friends , though she hadn't granted the app access to her contacts. Another one of her patients experienced a similar issue: A thirtysomething snowboarder oddly found himself getting friend suggestions for 70-year-old men with walkers — people he'd certainly never met before. He showed the friend suggestions to the psychiatrist, and both deduced the only tie was that they all visited her office on a regular basis. The psychiatrist now recommends her clients don't log into Facebook at her office, or that they don't even bring their phones into the office at all.Apparently, this location-based theory is not how Facebook's friend-finding works, though. What could be happening, however, is that all of these people began seeing one another on Facebook because they had this psychiatrist's phone number in their phones — a mutual contact. Facebook told Fusion in a statement that it couldn't confirm this was the reason, but explained that "People You May Know" uses a variety of data to source its suggestions, including mutual friends, your phone contacts, your school and work information, and networks you’re part of.This certainly isn't the first time Facebook has come under fire for "creepy" friend suggestions — or for the possibility that it is in fact using location to help determine whom it suggests. And right now, it seems there's little we can do to prevent this issue from arising. If you're seeing strange "People You May Know" cropping up, you may want to consider removing some private information (such as your phone number or workplace) from Facebook, being more mindful of where you log into the app, and even clearing out your phone of unwanted contacts. You can also teach the social network which "friends" you don't want to see suggested anymore by tapping the X next to their names While artificial intelligence algorithms are making many of our apps smarter and more useful, sometimes, as in this case, they can also be downright wrong.