I haven't kept up with it, but back in the day of Counter Strike there were VAC-disabled servers specifically configured for cheaters and it was very interestin

I haven't kept up with it, but back in the day of Counter Strike there were VAC-disabled servers specifically configured for cheaters and it was very interesting to see all of the various aimbots, wallhacks, etc going at it. Some of the cheats were specifically designed for these servers. As someone mentioned elsewhere in this thread, this was called HvH. Great stuff.