its a clientsided spoof from my understanding by changing something in the DLL you can change your Steam ID clientsided only which means servers can still get your steam ID by typing Status into console, and apparently the "yes , i am the real garry" achievement only checks clientside to see if the steam id matches garrys , and also recently a real steamid spoof has been fixed, which was something about stealing steam cookies, that was dangerous cause it was spoofed serverside aswell. what im trying to say IS ........... valve and facepunch doesnt fix shit before they make it,so the source engine IS FULL OF EXPLOITSSSSSSSSSSSS