All they have to do is shut down the Internet and communicate only through cellphone text messages. You will NOT know what is really happening in the world and people will easily be controlled.

"Did you get that message today from Biden? It said there is a fuel shortage! Hurry, get to the station and fill up while you still can!"

Gets to gas station and the line is out to the street. Now the person believes the lie. EVERYONE GOT THE SAME MESSAGE OF COURSE THE GAS STATION IS SWAMPED!

"Did you get that message today that said there is a new virus that is so deadly we can't leave our homes without a vaccination? Me too!"

Locks self in home while frantically trying to make an appointment for a vaccine. Can't get an appointment so tries to find a drive-up location but all are jam packed with cars.
Runs out of fuel waiting in line because they couldn't get any earlier.

See how easy this is to do by eliminating only one form of communication?