In Germany such stuff is handled by the "Ordnungsamt" (office of public order, roughly translated). They're not policemen so they don't have the authority to arrest, but they can and will issue fines for littering, graffiti, improper advertising and the likes.

This way police is free to handle actual crime.

I guess they are slacking in Berlin because the whole city is covered with graffiti and random advertisement trash on every traffic pole.

At least graffiti and trash keeps the rents down, plus it looks nicer to the eye than the bullshit uber-clean concrete crap that passes for "luxury flats" these days.

Landlords are asking 800 EUR cold for one room apartments, it is unfortunately not cheap enough :(

Indeed, "Ordnung muss sein, sagte Hans, da brachten sie ihn ins Spinnhaus" :D