https://www.techdirt.com/articles/20180410/17590439606/ftc-suddenly-remembers-warranty-void-if-removed-stickers-are-illegal-sends-out-stern-letters-to-manufacturers.shtml

The law has been around for more than 40 years, but the FTC only seems interested in enforcing it every so often. The tags slapped on electronic devices warning you that removing them will void your warranty? Complete horseshit. And illegal horseshit on top of that.

The 1975 Magnusson-Moss Warranty Act said manufacturers can't automatically void warranties just because owners have opened up their devices, performed their own repairs, or taken them to third parties for service. Nonetheless, the practice of sticking these little lies on electronics continues because the US government has yet to show an ongoing interest in protecting consumers from companies preying on consumer ignorance.