Any source for this ?

The main organizing actors are unions.

Protests are usually peaceful, but even then they are attacked by the police.

Rioters come mainly in 3 flavors:

• black blocks whose purpose is to create conflit showing the violence of the state
• opportunists who use the protest as a cover for looting (poor people) or damaging power symbols like banks or administrations (revolutionary people)
• peaceful rioters who got charged by the police and fight back.

Videos focus on violence. Peaceful protests are mostly ignored, as most media push an authoritarian agenda. Plus violence makes good pics.

Coordination is done via some posts on social media, details are passed on secure messaging platforms.

Damage to locals is supposed to be covered by the state, which is trying to pass a law passing the costs to all identified persons present without need of proof. Identified rioters can be sought after by the state, some end in jail. The ones who come rioting on purpose know how to move under the radar.

As for use of military force, it is being discussed. Armed forces are mostly far right, so the risk would be real.