If you are Spanish and are protesting the austerity measures, you might consider them for health reasons. Especially if you lean on the chubby side:
As is usual with unruly mobs, I support the police. Law enforcement is faced with an impossible job in these situations. They are confronted with massive numbers, instigators willing to pick fights, and photographers who will publish the most unflattering pictures. But not the action that brought them about. Yes, that knee in the back of a skinny 19 year old occurred because the punk threw a piece of cement.