Since Discourse is used around the world and laws are different everywhere, I think that all Discourse(-the-software) can do is make sure that all the underlying technical mechanisms are in place, like:
- making an admin contact email address available
- giving tools to moderators and administrators to moderate, hide, and remove content
- giving tools to users to flag inappropriate or unlawful content
- giving tools to moderators and administrators to ban users and block address ranges
(And Discourse does that very well)