Around a year ago I was pretty new to trading. A (in real life) friend asked me to broker an unusual for him, a Circling Hearts Handyman's Handle. I did it without checking his background information, and put a trade up on outpost. It turned out that my friend was premanently banned on outpost, which resulted in a permanent ban for me.
Never before did I infringe the policy of outpost, and I did not get a warning either. I simply got permabanned. I made an appeal, we are still talking 11 MONTHS AGO.
2 weeks ago one of the outpost mods, namely Toughsox finally replied to my appeal with nothing but. "No, you infringed on the Outpost rules, no trading for banned users."

There is endlessly many traders, higher tier traders than me, who have been assigned 1-2 week bans for offenses by far heavier than mine, regarding unusuals and items worth 1000s of dollars bought directly off scammers and similar things. The hat I got banned over was at that time worth roughly 60 dollars, and brokering for a banned user was never something I knew I was doing. A permanent ban is in no way, shape or form appropriate for the mistake I made.