Team Fortress 2, released by Valve in 2007, built much of its humour around clear class roles and automated defences, including the Engineer's Sentry Gun that locks onto opponents. Short alert cues and callouts from the game became easy to lift for videos because they are instantly readable even out of context. This spotted cue has since circulated on soundboards and in gaming edits as a shorthand for detection, letting creators turn an ordinary entrance, glance or camera pan into a mock tactical warning without needing any explanation for the audience.