Indeed, hypothetically, if a tiny game developer had gotten such a letter, they would probably be asking their friendly lawyer to find a moment to advise them,

Indeed, hypothetically, if a tiny game developer had gotten such a letter, they would probably be asking their friendly lawyer to find a moment to advise them, rather than saying anything publicly. I suspect a great many such extortion letters have been sent; let's hope they sent so many that the combined defense will be enough.