Correction, he's not banned, he's suspended for 7 (now 5) days, for litterally spamming the forums.
In our community standards, here's why he was suspended in fact, even if he already got a few warnings in the past:
Disruption…Posts which intend to disrupt the topic of conversation or steer the topic away from the focus of the forum and related news. Disruption can include harassment, multiple posting of the same post and posting completely off topic messages.
We can tolerate it easily, but between Saturday & Sunday, he posted about 80 messages, and at least 60 were unrelated or replying to old messages with one liners, and it pretty much messed up all the main forum so I had to take 1 hour of my time removing messages to get the real latest topics back on the front page.
Next Sunday, he will have back his posting previledges, it's up to him to use them wisely. I must say his attitude isn't something that actually helps, usually, most people are comprehensive, and I think I have a large history of being someone anyone can talk to and find a way to fix things, but...!