This sound is based on the famous Terminator 2: Judgment Day theme, heard in the 1991 film and closely associated with composer Brad Fiedel's metallic, industrial score for the Terminator series. Online, short cuts of the motif spread through meme edits, trailer parodies and character introductions because a few beats instantly signal menace, power and inevitability. It is still popular because viewers recognize the movie reference right away, even when the clip is used ironically over everyday footage.