No, I am not but i saw some people banned due to sharing of some link here even their intentions weren't marketing at all.
Sharing links would not get you banned from the forum, except the links contains malwares which would be harmful to those who visit the websites.
Newbies can also get nuked for spamming the forum with links from shady websites.
Plagiarism is copying contents and passing it off as your own creation, without crediting the source. This would get you a permanent ban.