Would this contract clause invalidate a class-action lawsuit?

As some of you may not be aware, the videogame hacking company MSX Securities develops and sells various hacks and cheats for many of the most popular online games. While the cheats and hacks are annoying, the server problems they cause have lately begun to cause significant down-time and loss of productivity, recruitment, and substantial damages. While an individual suit against a specific hacker would obviously be valid, it doesn't address the bigger problem of the company itself.

I am looking into the possibility of filing a class-action lawsuit against this company for various damages, but was wondering if a simple contract clause would really exempt them from liability:
"Liability clause: MSX Security can not be held responsible for any illegal actions performed by the end-user."
Would this really exempt them from such a suit? Or is that just bogus?

Re: Gun comparison:
No it's nothing like blaming a gun company for a murder. Whereas a gun company doesn't make guns explicitly for murdering people, MSX advertises their products as the best way to avoid detection on ranked servers (a legal violation in itself). This sort of thing falls under the domain of p2p programs like Napster (the old one). They advertise how great it is at doing illegal things, but cover their asses by saying its for "educational purposes only". Meanwhile they post videos on their site of individual users breaking various state laws by using the product on servers like MINE. But how much of a benefit would it be to the gaming community to file a suit against 14 year old little johnny noobface.

You should contact an attorney. The answer to your question depends on a lot more information. Most attorneys will not give legal advice like that over the internet. I wouldn't.

I think that exempts them.

And how can MSX Security really be held responsible for the actions of hackers?

That's like the woman in Florida that tried to sue the gun manufacturer because her husband was shot by a bad guy.