OK I'm playing a match and inadvertently think I get called a hacker after acing with a grab someone says something to the tune of "yeah right, sure." First thing I do, start fraps and begin recording. The demo ended up being 2.5 gigs, and I really didn't even get called a hacker. Regardless, a thought crossed my mind which most likely isn't original but I haven't heard it from anyone personally, except in CSS. Before every match, have each player take a screen shot of both teams and scoreboard. I'm not familiar with hacks (because I've never used them) but, I would assume that you cannot turn them on and off in-game (can anyone back me up?) If anyone leaves and comes back, or new players come in, the same has to be done (maybe in observer?). Maybe you could set up a thread just for the purpose of uploading these screen shots and validating the players abilities, as well as the credibility of the clan matching. This way, if a team refuses to do so, they would obviously have something to hide and most likely would not get asked to match anymore. Just a thought....
***Edit
Someone just informed me that its easy to turn hacks on and off in DP. Scratch that I guess? At least it would deter spiking, and it seems that Jitspoe has a good handle on wallhacks.