After finding out that people got banned because of this.
"The problem was that Steam would fail a signature check between the disk version of a DLL and a latent memory version," Newell explained. "This was caused by a combination of conditions occurring while Steam was updating the disk image of a game."

Newell clarified that the error wasn't something inherent to Modern Warfare 2, and said Steam allows Valve to identify and reverse erroneous bans.

I haven't been on in a long time. So I decided to contact steam support after finding out about the erroneous bans.

Here's how support went.

1 Message by you on Wed, 21st Aug 2013 4:00 am
Still waiting for my ban to be reversed, and my copy of left 4 dead 2.

Originally posted by Steam Support:

2 Message by Support Tech gregoryy on Wed, 28th Aug 2013 5:14 pm
Hello,

Thank you for contacting Steam Support.

We apologize for the delay.

Our system indicates that the account has been permanently banned by the Valve Anti-Cheat system (VAC) for use of cheats or other unauthorized modifications. Steam Support is unable to lift the ban.

We will not disclose the cheats which were detected, nor will we provide the date and time the infraction took place. VAC has confirmed that the ban on the account was applied legitimately.

This ban applies to a Steam account (regardless of who was using the account at the time the infraction occurred). The use and security of the Steam account is your responsibility.


To see which games your VAC ban affects, please launch Steam and go to Steam > Settings > Account tab > select "Click here for details" under VAC Status.

You may still play single-player and connect to non-secure servers (if applicable).

We cannot move game subscriptions from accounts which have been banned by VAC.

3 Message by you on Wed, 28th Aug 2013 8:35 pm
So what your telling me, is I'm being singled out when everyone else had theirs reversed. People have already complained, and had their bans reversed. Do you want me to quote the article? BTW the ban isn't recent, and steam has publicly admitted to the error. I don't get online much, but I just recently seen that this also happened to others and theirs have been resolved. The only thing I want to know is why hasn't mine, when everyone else's has.

Originally posted by Steam Support:

4 Message by Support Tech gregoryy on Thu, 29th Aug 2013 11:23 am
Hello,

I understand your frustration in this matter; however, our system has confirmed that the ban was applied legitimately. A VAC ban applies to the game(s) regardless of who was using the account at the time.

It does not matter if you let someone use the account, or if the account was being used without your knowledge. It is your responsibility to safeguard your account against such activities.

I am sorry, the VAC ban on the game(s) will not be removed.

Before continuing to use Steam and Steam games on your computer, please remove all cheats from your system. Failure to do so may result in further VAC bans on the account.

Please refer to the Steam Subscriber Agreement and the Rules of Steam Online Conduct if you wish to review our policy regarding this matter.

5 Message by you on Thu, 29th Aug 2013 5:37 pm
As copied.

Valve Bans Modern Warfare Players By Mistake, Apologizes With Free Left 4 Dead 2
Were you wrongfully accused of cheating and summarily banned from the PC version of�Modern Warfare 2�recently? You weren't the only one. Valve's anti-cheat software goofed and they're offering free copies of Left 4 Dead 2 as an apology.P
Many players of Call of Duty: Modern Warfare 2 were surprised to find their Steam accounts banned this past weekend by Valve's anti-cheat software, more succinctly known as VAC. Valve president Gabe Newell says that was mass banning a mistake and offered an apology to those affected.P
In addition to restoring players' access to the game, Valve is giving players a copy of�Left 4 Dead 2�and one to gift to a friend, along with an explanation of how even players exhibiting good behavior were hit with the banhammer.P
Read Newell's message to Modern Warfare 2 players below and take comfort in the fact that you totally did nothing wrong and you're�not�crazy.P
Hello,
>Recently, your Steam account was erroneously banned from Call of Duty: Modern Warfare 2.
>This was our mistake, and I apologize for any frustration or angst it may have caused you.
>The problem was that Steam would fail a signature check between the disk version of a DLL and a latent memory version. This was caused by a combination of conditions occurring while Steam was updating the disk image of a game. This wasn't a game-specific mistake. Steam allows us to manage and reverse these erroneous bans (about 12,000 erroneous bans over two weeks).
>We have reversed the ban, restoring your access to the game. In addition, we have given you a free copy of Left 4 Dead 2 to give as a gift on Steam, plus a free copy for yourself if you didn't already own the game.
>To share your extra copy of Left 4 Dead 2 with a friend, you can 'Manage Gifts and Guest Passes' from the 'Games' Menu in Steam, or visit this article on the Steam Support site for detailed instructions: https://support.steampowered.com/kb_article.php?ref=4502-TPJL-2656.
>To access your own copy of Left 4 Dead 2, visit your library of games in Steam. If you didn't already own the game, it will now be listed among your others there, and is available for download immediately.
>Regards,
>Gabe Newell

Originally posted by Steam Support:

6 Message by Support Tech gregoryy on Fri, 30th Aug 2013 12:02 pm
Hello,

Unfortunately, we will be unable to assist you further with this issue.

Thank you for contacting Steam Support.

So since I'm not a no-lifer and get on Steam everyday, I'm giving the run around and the problem doesn't get fixed. So the same system that messed up is also saying the ban is legitimate. All I want is what everyone else got. Why am I being singled out?