Lowfyr. Game-Deception lives under the GPL. Honestly, if you ever visit their Code section on their forum, you would know that, if of course you don't already.
GPL states, that a person can take anything released under the GPL, and sell it, modify it, release it, and do anything they want with it, since the original author is basically giving it out.
Maybe you have heard of PearPC? It's a Mac OS X Emulator for the PC. Well, it's open source and under the GPL. A company named like, Maui-StreamX or something took their code (which was proven they stole it) and compiled it all with a new GUI and started selling it as, "CherryOS." Maybe you've heard of that? It's always coming up in the news on Slashdot.
PearPC developers can't sue them or anything, can only cry about it and talk shit on CherryOS, because they released their code under the GPL. It's basically what goes on with Counter-Strike cheats.
Also, you have to realize, that, MSX doesn't sell cheats specifically. MSX sells VIP accounts on his website, which leads to private forum access, more community stuff, access to cheats, etc. He isn't selling each cheat.
Although, he is selling a cheat named XeoN or something, because the author spoke to MSX and they worked out a deal, so he would sell that cheat directly and they would split the money.