Sure. Sometimes instigators are seeded throughout a crowd (especially crowd of protesters) to get them to shout certain things or steer the protest in a certain

Sure. Sometimes instigators are seeded throughout a crowd (especially crowd of protesters) to get them to shout certain things or steer the protest in a certain way/direction. Humans also have vestiges of herd behaviour. For example, if one person decides to cross the intersection on a red light (especially pedestrian) then more people are likely to follow even if they would wait for green light otherwise.