Has this ever happened before? Yes. I have had CA's revoke a few certs because the private keys were not handled correctly. It was actually company policy to

Has this ever happened before? Yes. I have had CA's revoke a few certs because the private keys were not handled correctly. It was actually company policy to do so. If you mean a CA revoking a cert because of a site's behavior, yes and certs also get issued to federal agencies for domains they seize. Most of the instances I recall were related to software and music pirate sites.