Disadvantages

  • VAC cannot detect 'content hacks', where, for example, texture transparency and color are manipulated, since they do not involve modification of any program code. In the Source Engine the option to create "pure" servers (sv_pure) that prevent custom content from overwriting the game's defaults was created to alleviate this
  • Valve Anti-Cheat - Wikipedia, the free encyclopedia
Unfortunately, this happens a lot, especially on the gun game server.
Just letting you guys know whats really going on.. and how easy it is to google " mathack " and will prob send you straight to it.

Needs to be fixed.