My XBL 2001 account got permabanned with 10~ years of purchased content on there, all my network of friends and leaderboard achievements and the likes, the works. Lost access to literally everything that wasn't on-disc, and appeals didn't help.

I'd had one genuine temp-ban beforehand, and my theory is over the years I got enough reports from opponents that they just built up into saying t'ra to my account and purchases. Yay, right?