GitHub works well with Tor except for the signup step (https://github.com/join).

GitHub employs a broken CAPTCHA that **prevents** signups over Tor. The CAPTCHA simply does not render properly. It is unclear whether this is intentional or not. The error message is:

`Unable to verify your captcha response. Please visit https://help.github.com/articles/troubleshooting-connectivity-problems/#troubleshooting-the-captcha for troubleshooting information.`

Very frustrating for anonymous souls.