> Otherwise, I will have to transfer information about you to lawyers who will cooperate with github.com and Chinese government to physically find you and stop the illegal use of licensed content.
This is by far the worst takedown request I've ever seen in Github. The physically find you is especially concerning, since the owner of the repository seems to be a Chinese national.
Apparently by the time the takedown was written, the API was public but the documentation was taken down. The next replies don't make it better, and it seems they don't have a leg to stand on to send a proper DMCA.
I also had no idea they belonged to Ultimate Guitar. Honestly I lost some of the respect I had for MuseScore and Audacity teams after seeing this.
This is IMO worse than the youtube-dl debacle.
EDIT: The same developer who wrote the email seems to be making threats involving the police in another repository: https://github.com/Xmader/musescore-downloader/issues/42#iss...