The laws with papers published at universities in the U.S. typically are, those papers become the legal intellectual property of the university itself. This is in effect what it means to publish a paper in the first place, that the words no longer belong to the author but are now in the custody of the university, or book publisher.
I’m not a lawyer or anything that’s just my understanding of how that works.
Forums can be similar, but definitely depends on the country where the servers are and choice of administrators how they want to run things.