Treyarch is defiantly being heavy-handed in handing out the bans. A friend of mine got banned for having some PC issues, which corrupted some files and TAC picked this up and swung the ban hammer. It's very black or white any difference in the games code and it's an instant ban!!!
I believe TAC scans your PC during games and if the game code on your PC is different from the TAC model, then the ban hammer falls. Regardless of whether it's a genuine mistake or from using something not built into the game by the devs. Either way if it ain't as per their model the ban hammer gets a workout.
When MW 3 first came out there were over 2000 players on HC TDM at peak times I never saw more then 1000 playing the same in BO 2. I don't think the game will last that long, especially as they are limiting the amount of HC game modes as well. There's already threads on the official forum's with lots of complaints about all of this. It looks like 3arc's after sales service is not customer friendly. Their attitude may change once the first map pack is released and sales are way down their on expectations???