I think what buboard is talking about is that CAs can revoke certificates that they've issued, and can refuse to issue certificates to particular sites. Someone

I think what buboard is talking about is that CAs can revoke certificates that they've issued, and can refuse to issue certificates to particular sites. Someone might pressure CAs to do this for a content censorship purpose, much in the way that people pressure other kinds of intermediaries and technical infrastructure providers when they find some online site or content or activity objectionable.