Who would've thought no one wants to be recorded or be monitored while driving
It's when you have a reason for doing or not doing something, and you assume you're the only one, but really, everybody else has the same reason.
As a result, everybody is passive and doesn't act like they would if they knew everyone agreed.
It's the opposite of https://en.wikipedia.org/wiki/False_consensus_effect
Ah, this is it: https://en.wikipedia.org/wiki/Pluralistic_ignorance
The nice thing about a "false consensus", of course, is that someone who believes in it can tell others they are victims of "pluralistic ignorance" and once enough people are brainwashed, it's a true consensus!