Here’s a fun fact: If you use Steam for your games—let’s face it, you do—there’s a chance Valve’s Anti-Cheat System been taking a look at all the websites you visit and sending a list back to home base. Why? No one knows for sure. The discovery comes by way of SHG_Nackt who claims to have found a suspicious little piece of code that appears to mine your DNS cache for a list of domains, hash them, and send them back to Valve for perusal: “You don’t have to visit the site, any query to the site (an image, a redirect link, a file on the server) will be added to the dns cache. And only the domain will be in your cache, no full urls. Entries in the cache remains until they expire or at most 1 day (might not be 100% accurate), but they dont last forever.” Presumably, the idea would be to collect a list of hashed domains from users, and check them against a list of domains that are widely known for supporting cheating or hacking on VAC-protected Steam games.