Maybe “arguably illegal”? The RIAA’s argument is that youtube-dl is a tool for circumventing copyright protection, which is related to the concept of piracy or

Maybe “arguably illegal”? The RIAA’s argument is that youtube-dl is a tool for circumventing copyright protection, which is related to the concept of piracy or copyright infringement, but prohibited by different laws. Marketing a circumvention tool can be illegal even if there are ways to use it that don’t infringe copyright. https://en.wikipedia.org/wiki/Anti-circumvention https://en.wikipedia.org/wiki/Anti-circumvention