Internet-connected servers are insecure! News at 11.
I don't understand your comment... Do you think SF.net, kernel.org, and GitHub all connected somehow? Beyond the trivial circumstance that connects them banks, the US military, NASA, Sony, and all the other competently-administered websites getting hacked every day?
Happily, because of Git's hashing scheme, it's not very easy to make repo modifications without having people notice.