[CaptainZapp]

Easy:

Hand every tourist a brochure about the Do's and Dont's. Aka, like Singapore prints warnings (DEATH TO DRUG TRAFFICKERS) on their landing cards.

If laws and rules are disrespected fine the sweet bejeezus out of those assholes (like in the thousands of $ range) and ban them from the country (or ideally, from the Schengen room) for 5 to 10 years.

The problem will solve itself in short time.

[rando444]

We have something like that, which you find in the airport and various places.

https://www.inspiredbyiceland.com/icelandicpledge/

The people that need to read it the most though, either don't or don't care.

[CaptainZapp]

This should just be common sense to every traveller anywhere.

It's really a sad reflection of where we stand that this does not seem to be the case.

Thanks for the link.