I was once banned from uploading indefinitely. I know why I was. Luckily, in my case, I found a GP who believed what I said and, I assume, put in a good word for me. I was unbanned after sending in a ticket.
How did I get banned? I was a noobie player and was informed by another that if an upload was rejected I should spam it and it will eventually be approved. The reason was that the system was a robot and had moments of being dumb. I was set up, in a sense, but I don't believe the player had any malicious intent.