This sound is associated with Lion, an operator from Tom Clancy's Rainbow Six Siege by Ubisoft. Players know it from the scan mechanic that punishes movement and creates a sudden stop-or-be-seen moment during rounds. Because that mechanic is so recognizable, the audio spread into gaming clips, TikToks and meme edits as a shorthand for detection, exposure and panic. It stays popular because even people who do not play Siege can immediately understand the joke: somebody got spotted and the pressure is on, much like an enemy spotted callout.