Well shit, remember the videos of those dumbasses all crowding Clearwater Beach in Florida last week for spring break? Those assholes were slow on the uptake to stay the hell away. So the societal proof was there for people to not do it, but they did it anyway.
Lagtime. So now, by the time the all clear is sounded, these jamokes will be another month slow on the uptake that the world is safe again. GIGO
Different people get their social proof from different places. If everyone on your facebook/twitter says they're going on spring break, that's going to be your social proof.
Example from a democrat politician in NY.