The phrase FBI, open up has long been a staple of police dramas and parodies, but online it became a standalone meme sound for fake raids and surprise entrances. Creators on TikTok and YouTube reuse it to interrupt gaming streams, reaction videos and pranks, often starting with door knocking before the shout lands. Its appeal is its instant recognition: listeners immediately picture officers at a door, so a single line can set up a joke without any explanation, which keeps it in regular use years after it first spread.