We may, but have no obligation to, remove Content and Accounts containing Content that we determine in our sole discretion are unlawful, offensive, threatening, libelous, defamatory, pornographic, obscene or otherwise objectionable or violates any party's intellectual property or these Terms of Service.

and

If your bandwidth usage significantly exceeds the average bandwidth usage (as determined solely by GitHub) of other GitHub customers, we reserve the right to immediately disable your account or throttle your file hosting until you can reduce your bandwidth consumption.

I wouldn't worry too much about it.

https://help.github.com/articles/github-terms-of-service