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I was alarmed to see that someone uploaded one of my old GPL'd projects to Github. I don't use Github or any other Microsoft product. Github has refused to remove it however, and suggests I contact the uploader who is completely anonymous and cannot be contacted.
Even though the GPL allows copying, this is alarming because Microsoft is a malicious company, both today and in the past. The act of uploading could be used by their corporate lawyers to claim that they can automatically abscond with my copyright, if their ToS is written to assign copyright to them. I've seen this before. Sourceforge did it in the past.
Years ago, the "fine print" on Sourceforge literally said that by uploading code you are assigning copyright to them, no matter what license is applied to it. They assumed the author was the uploader. But it was a clear attempt at theft-by-lawyer. All Microsoft has to do is change their fine print for 1 day and they can claim that my code is theirs.
This question is unlike any other on SO because it is clear in meaning and not a chameleon question.