Nice! So announcing "Keine Werbung" on my letter box becomes now also a legal binding? I also wonder about all the announcement on t-shirts. Hmm.
https://dejure.org/gesetze/UWG/7.html
Sure, theory and practice and sueing offenders are all different things, however most obey that here I'd say?
Perhaps advertisement is only something big companies do? /s
https://dejure.org/dienste/vernetzung/rechtsprechung?Gericht...
If their job is to litter, then tough luck.
I also send nasty letters to parties who consider themselves exempt from that before elections (they're not).
What pisses me off is that they advice to do the same in my country when I complain about leaflets from Lidl, Kaufland, Rossmann and others. Take your silly practices back to Germany, I don't need to label my postbox NOT TO RECEIVE your spam over here. "No spam" is the default without any label.