As I wrote previously, Modern Warfare 3 had a lapse in its clean record of being largely free from hackers and cheaters, not to mention Infinity Ward’s very strict banning policy, which will come down on you like a ton of bricks if you get caught. On the ball as they claim to be, they’ve cracked down and taken action.
A developer on the Call of Duty forums said that lobbies which were made to reduce player ranks were made to be public before the developers realized. An Infinity Ward developer said “A modding group created a viral mod, which we prevented from spreading within twelve hours yesterday, sadly, in ‘protest’ at our ability to disable this they are now inviting players to private matches where they reset their stats.”
They very quickly forget that Infinity Ward is smarter than the average bear and just as fast as one. The issue is being stomped on and they continue to stomp it out.
Infinity Ward has stated that you must be wary of any invites to private matches from anyone not on your friend list. Even if the problem of the mods and hacks has been resolved in public lobbies, private ones are several times harder to enforce. Infinity Ward has also stated that they are working on this issue and have backed up player stats prior to this incident, and many who were affected will be able to have their stats fixed. The system was put into place the moment they learned what was happening.
Basically: If your stats have been affected, don’t worry.
Activision Support has recommended that you report anyone and everyone you believe to be cheating through the in-game report feature. They also said that if you get a video of people cheating, tweet it to @InfinityWard and they’ll see it.