Also, what information is it based on? It’s one thing to mistakenly (or deliberately) claim that the threat level is higher than it actually is, but what about the reverse error? What if there is a gap in the intelligence and we’re told the threat level is low, only for there to be a massive attack somewhere. Presumably, when the government/security forces think the threat is high, that’s paradoxically when there’s least likely to be a “successful” attack. When the government think the threat level is low, isn’t that going to be the best time for terrorists to strike, therefore making the *actual* threat level high.

Also, people are notoriously bad at being able to interpret probabilistic information – I really do think this is such a pointless exercise, its only possible purpose can be to manipulate people.