Nintendo has filed copyright claims against the Super Mario 64 PC Port that was released this month.
They are reportedly using the law firm Wildwood Law Group LLC.
This fan-developed Port made headlines for having 4K resolution and ultra-widescreen support, and the ability to play it with an Xbox Gamepad.
This project ran natively in DirectX 12, unlike other versions of the game playable on PC through emulators.
Nintendo is furiously trying to get all the copyrighted content removed from YouTube, Reddit, and every other website and platform that it has popped up on. Although there will always be a copy for anyone who looks hard enough.