From what I remember, the suspect is believed to be the leader of an anarchist group responsible for squatting places, to struggle against the move of wealthy people to North-Eastern Paris.

They have made the news for squatting one place in particular: the restaurant "Le Petit Cambodge", as it is one of the restaurants targetted by terrorists on November 13, 2015.

Here is an article in French about them: https://www.lefigaro.fr/societes/a-paris-un-local-du-restaur...