Algorithms are patentable, not copyrightable. FISR could have been patented (and be now in the public domain anyway), but only it's specific implementation in

Algorithms are patentable, not copyrightable. FISR could have been patented (and be now in the public domain anyway), but only it's specific implementation in DOOM is covered by copyright. Also, your argument follows a composition fallacy: emergent properties exist, and thus you cannot simply say that because each individual piece of a whole is trivial, the whole is trivial. Heck, software pretty much by definition goes against that. For relevant precedent, there is no shortage of information that becomes classified when in aggregate. Knowing where a certain piece of infrastructure is isn't likely classified, but knowing where all the strategically important pieces of infrastructure are certainly is. Which is why the question isn't whether the users of Copilot are infringing someone's GPL (they'd likely have a solid defense based on the individual piece not being sufficient to hold copyright protection), it's whether Copilot itself constitutes a derivative work of its input data, which it consumed as whole (copyrighted) works.