Same in Germany. Graffiti everywhere; walls, buildings, fences, signs, historic monuments. It's awful and I don't know why they can't manage to do anything about it, but it also seems like no one cares about it as a problem to begin with. To me, such an individual invasion of the public space seems like a mockery of the common trust and the notion that the Europeans (and the Germans especially) have some sort of communal responsibility.