It's about domain names. Literally. Not about the purpose of the websites hosted on that domain. If it were about the website, it would be rather impractical to adhere to every nation's laws. Itch is illegal in Russia for it's lgbt-friendlyness alone.
You can have names that are offensive, sexual in nature or even illegal in some countries. Try insulting persons with a phrase and register that as a domain name. That sort of thing.
Though I have trouble of the concept of a porno-graphic name. Does this mean certain emojis or what ;-)