github-email-thief
Github (and Bitbucket as well) expose the vast majority of their users’ email addresses via commit metadata.
As a proof-of-concept, I made a single page app using Angular + the Github API to demonstrate how browse-able/scrape-able this contact information is.
You can check if your Github username is affected.
You can read about how to hide your email address here.
The project is non-commercial and MIT-licensed.