After the new update of alterIW server, the bans appeal it's the message you get after you open the game ,,you have been banned from Modern Warfare 2.''
Just like in this example!
If you don't find any players, in the right corner of your screen, it says ,,0/0 player'', that means you did the patching wrong.
I hope this is explicit enough for you, so starting hundreds of threads like ,,am I banned?!'' won't be necessary anymore.
However, who will start this kind threads, will get thread closed and a day off.
There might be a way to get unbanned, but I can't guarantee for it. (never tried it)
XUID unban tutorial.
Or try changing your OS (Windows) and IP.
Also reinstalling the OS, might solve the problem.
~COD Staff