Well that’s not creepy at all: Facebook can recognize you in photographs even if it can’t see your face.
“An experimental algorithm out of Facebook’s artificial intelligence lab can recognise people in photographs even when it can’t see their faces. Instead it looks for other unique characteristics like your hairdo, clothing, body shape and pose. Modern face-recognition algorithms are so good they’ve already found their way into social networks, shops and even churches. Yann LeCun, head of artificial intelligence at Facebook, wanted to see they could be adapted to recognise people in situations where someone’s face isn’t clear, something humans can already do quite well.”
Or in my case, it’ll recognize me by the brand of paper bag I put over my head.