They are practicing what is called Mid Level Violence. The idea is to provoke people into physically attacking them by being annoying or insulting enough (which that sign certainly passes the threshold). Then, they film the inevitable confrontation and release edited footage that makes them look like the innocent victim. This is a classic Marxist tactic and has been used for many decades. It is starting to become less effective as people use legacy media less and less, instead relying on online content which is very quick to unravel the missing context of these situations.