Nobody is going to learn all the laws of a country. When the laws/custom of a country are so different than yours that a trivially legal act in your country becomes highly illegal in that country you should avoid that country because who knows what else you'll do that'll get you into trouble.

Iran in particular has started to take foreigners hostage to trade prisoners with abroad. Laws don't matter much in Iran.

Same in Russia. Evan Gershkovich has been sentenced to 16 years in prison today.

Here is the case of a German citizen likely caught as hostage: https://www.bbc.com/news/articles/c28eym731zjo