Who go to places and film, post offices a library seem to be the favorite sites. But a lot will go in police stations, federal buildings, fedex, prisons and even military installations.
The ruse is first amendment right to film in public but the goal really is to get a confrontation with employees, security and or police. They post them later to their channels claiming rights were taken from them. This in turn gets gullible followers to donate money to the "cause"