Official reason for blocking: the site hosts texts describing methods of suicide. Because Github uses HTTPS only, it's impossible to block only the offending pages, so the whole IP range is blocked. Github ignored their requests to remove the offending content, so the site remains blocked.

I hope Russian citizens get a big fat boost of morality from blocking Github.

Really, it's not the alcoholism, injustice, corruption, poverty and now economic collapse that causes people to commit suicide in Russia, it's... Github !!

This just shows how braindead the people holding power in Russia are. Oh, and these censorship 'laws' have been adopted by people who've stolen billions and who've built a corrupt police state, which is really scary, because the same people have their fingers on the red button.