I know that they tried to evict the people in the forest in 2018 and a bunch of people got arrested because they resisted the eviction. Later on they walked it back and let them stay but still some people got arrested not because of violence but because they occupied the forest.

The prosecutions are not because they camped there, but what about those who were arrested and not prosecuted? just taken into jail, strip searched, then let go outside the police station after a night in jail when nobody can find where they are? Without any prosecution because the police cannot stick them anything? The violence against the police is mostly not ideological, it's caused by a deep anger about how people are treated, getting teargased for nothing, or prevented from moving.

Also now with social media, you can find a lot of example of what are called in France "Appariteurs" who often start the mayhem then leave through police lines without getting arrested.