This query is a bit and could refer to a couple of different things depending on what you're looking for:
: "Facecast.mp4" sounds like the title of a lost media creepypasta or an ARG (Alternate Reality Game) story, similar to "Smile.jpg" or "username:666." Facecast.mp4
: Usually, these stories involve a user discovering a corrupted video file on an old hard drive or a deep-web forum. This query is a bit and could refer