Security cameras have existed for decades, but they've really reached critical mass in the past few years. Many of us have them in our homes, while some of us may have to watch them as part of our job.
Naturally, since these cameras are rolling 24/7, they're bound to pick up some weird stuff. This r/AskReddit thread asked Redditors about the creepiest thing they've ever seen on security cam. It's a great read, but you might want to turn the lights on first.
Note: Some of these get quite dark, so read at your own risk. Seriously.