Rubbish banners

One of the first things that has called my attention when I first arrived in Hamburg was the publicity banners that you can find in streets litters spread all over the city.
As a public campaign for people not to throw rubbish to the ground, I find them quite well done. Whether they work, it is a completely different question.
I've picked a couple of examples:

Black Hole looks for residual materials

I have dirty fantasies

I'm well placed!

Stay clean, my Hamburg!

Whn I grow up, I will be a container

You can reach me out of the working times

Make it flat!