This is more or less about TF2. The game is still insanely popular but it has a huge bot and hacking problem ongoing for _years_. But Valve doesn't care about it or more like if you know how Valve works no one is working it (all aboard the Steam Deck!). They made a tweet [0] recently that they "hear" the community but that's all after all those years.
Anyways the dedicated community made a TF2 mod which is basically rolling back to the game almost into its original form [1]. It is however based on previously leaked source code so most likely not legal at all. Valve asked to disable downloads and the mod creators did however recently Valve stopped any communication (besides that tweet) so they just allowed downloads again [2].
And the latest step in the back and forth is this news about disabling source code access.
Valve is a huge mess as we seen it here on HN too https://news.ycombinator.com/item?id=31218309
0, https://twitter.com/TeamFortress/status/1529970640224018433