I found this one out when I got my hands on Steam Family Sharing BETA.
I got a TAC banned bo2 account for over a year now, and guess what... I can share the game on another account and play it! So the ban was kinda worthless since I can still play with the other account. VAC bans do not show in your game library when you share those vac banned games. So yeah, IAC or TAC banned? No fucking problem.