> If you set your pages and repositories to be viewed publicly, you grant each User of GitHub a nonexclusive, worldwide license to use, display, and perform Your Content through the GitHub Service and to reproduce Your Content solely on GitHub as permitted through GitHub's functionality (for example, through forking).
For those interested, GitHub's entire TOS is written in a very approachable way.
Semi-related question: Assuming I drafted up a software license with generally permissive terms (freedom to use, modify, sell, etc.), but included some perverse clause that would forbid forking (such as only allowing the software to be distributed from the canonical repository on my profile), would I have legal grounds to request repository removal from GitHub if someone pressed the repo's fork button?
Relevant excerpt:
> If you set your pages and repositories to be viewed publicly, you grant each User of GitHub a nonexclusive, worldwide license to use, display, and perform Your Content through the GitHub Service and to reproduce Your Content solely on GitHub as permitted through GitHub's functionality (for example, through forking).
For those interested, GitHub's entire TOS is written in a very approachable way.
https://help.github.com/articles/github-terms-of-service/