There are also squares on the yellow shirt of the guy on the photo and at the bottom of a piece of a iron gate.

If it comes to smoking and no smoking areas, I never saw that many smokers and smelled that high amount of marijuana as in this city.
Smoking is already forbidden at public places but it feels no one cares in Amsterdam and the police everywhere present doesn't act.

What to think about the next shield? It is forbidden to smoke marijuana...