Movie-plot threat
A specific, cinematic attack scenario that attracts outsized defensive spending precisely because it is so easy to picture.
Bruce Schneier coined the phrase in 2005. Governments and companies defend against the shoe bomb or the subway gas attack someone just described, while the attacker simply picks another target. Every defence against a particular script moves the threat one block over and costs as much as the last one.
His alternative was to spend on things that work regardless of the plot: intelligence, investigation and emergency response. To show how cheap frightening scenarios are to invent, he ran an annual Movie-Plot Threat Contest on his blog from 2006. The idea is a close cousin of security theater and a useful reminder of what a threat model should not look like.