It is not tolerated in tue forum but it is not a crime. Crime is too serious and Plagiarism is not a kind of serious crime.

You plagiarised and your posts are reported, you consequently will be banned.
Crime is a commitment of someone either intentionally and unintentionally, so anything that make you to get banned in the forum is a crime,  I don't know what you understand by a crime and how you define your own crime, because I believe that without abiding on the rules and regulations of the forum we are automatically or basically on crime of the that can result out many things, some people has be ban on the forum in the respect of committing plagiarism and they later get unban depending the mistakes of the person, theirs is some plagiarism that the mod can be consider unintentional and when numerous members solicits on behalf of the user it can get unban, but if the commitment is obvious in which everyone have detect that the gravity of your plagiarism is intentional it will remain unban because the user have disobeyed the rules and regulations of the forum. That is while its called crime because you disobeyed the rules. When someone first registered in community and the link that will given to person by other members is to read the rules and regulations of forum.