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It's called California's Title 20. It's part of a much bigger set of laws and regulations that affect many other things besides computers.
I know that Linus Tech Tips is going to produce a video where they custom build two PC's, one that's a low tier computer that's hardly fast enough to game on
that doesn't meet California's Title 20 energy requirements and one that's, as he puts it, "balls to the wall, top-of-the-end" gaming computer
that does meet California's Title 20 energy requirements.
Note that Title 20 only affects prebuilt computers. If you custom build one yourself you can build it however you like, even in California.
From what I've seen it seems that the media has taken this regulation out of context and hyped it up making it look like California is against PC gamers or something like that.