Pirated video games SOURCE CODE - eviltoast

So there are multiple sites&groups that pirate video games especially on PC. I was wondering if there are places on the internet where you find source code for games especially the highly modifiable ones like Half Life 2/Portal and Skyrim. Or groups that crack into the source code of games (or even software in general), not only for PC maybe PS, XBox or mobile too, and share it. I just wanted to see some code samples of games or their engines, maybe I get hooked into video game design. Shout out to Valve for sharing a lot about the creation of Half Life 1