Google Search: Inurl:server Filetype:key “-----BEGIN RSA PRIVATE KEY-----”
Hmmm my idea would be<p>"Hello from github,<p>We detected that you uploaded credentials to NAME_OF_REPO. We strongly advise against this as it allows attackers to easily gain unauthorized access to your software and infrastructure.<p>Have a look at this blog where we discuss alternatives"<p>EDIT:
Just to be clear, I'm not suggesting a ban at all, just a friendly email in response to commits that introduce credentials to public repos