I think, specifically with regard to 'self-defense' and 'non-agression', that it is typical that the BBC commented on a image similiar to the one posted above that 'the police are charging the anarchists away with water'. Please. If you want to know who starts the riots look for the ones that come prepared for it.

As far as the ideological and philosopical arguments I would refer to https://hetanarchisme.blogspot.nl/p/documentaires.html which has a bunch of good documentaries about a bunch of issues. Thanks