Comment Re:Illusion of privacy (Score 2) 224
It's got nothing to do with the private key.
NSA goes to Verisign (for instance). Says "please sign our key for google.com". Verisign signs it. NSA intercepts traffic between google.com and you. Browser deems cert as valid, as Verisign signed it, and you seem to be connecting to google.com.
The CA system is weak because so long the connection is signed by a CA in the browser's list, the browser doesn't care which it is, even if it changes on a daily basis. If you can convince any CA in the list to sign what you need, you have a way to set up a MITM attack the browser won't warn you about.