Valve has been waging a war on cheaters on its service for years with the help of the Valve Anti-Cheat System (VAC). If someone installs a cheat intended to give them a leg up on the competition, VAC can detect it and ban the player from further online Steam play with that title. Valve is always tweaking the way VAC works to stay one step ahead of the cheaters, but some gamers recently wondered if VAC had gone too far by digging around in gamers’ browsing history.The accusation came via a Reddit thread where a user reported what he found upon decompiling the VAC module. Apparently, it was reading all the domains listed in the computer’s DNS cache and reporting back to Valve. Many Steam users interpreted this behavior as proof Valve was storing a list of every site they visited.If it was true, it would be a serious breach of trust from a company that the community usually trusts implicitly. Was it possible Valve had overreached in its efforts to find the cheaters? None other than Valve CEO Gabe Newell took to Reddit in order to explain the situation and assuage all fears.According to Gaben, VAC was examining the DNS cache of user machines for a brief period as an anti-cheating measure, but it’s not what it appears. The people who make kernel-level cheats invest a lot of time in it, so they want to be paid. These folks have actually started using DRM that phones home to a server to make sure a user has paid to use their cheat. VAC was merely looking for the address of known cheat DRM servers as a way to confirm a machine had cheats installed. If found, the addresses were hashed and sent to the Valve servers to be double checked. If that confirmed a player had cheats installed, a VAC ban was given.Newell explained that VAC isn’t even using this approach to catching cheaters anymore. The cheat makers have already gotten wise and now manipulate the DNS cache of client machines so their DRM servers don’t show up. While it’s a moot point now, Newell stressed Valve does not now, and never did have a full copy of anyone’s browsing history. So there’s probably nothing to worry about, but this little incident did offer an interesting look at how VAC works.