The only thing separating a self signed cert
from one obtained from a CA is that the CA
has some of your contact info
Most CA certs are domain validated these days, which means you have to demonstrate control of the domain to get the cert. it wouldn't take a whole lot of effort to
bypass their checks
It's pretty hard. If you get a CA to issue you a cert for a website you have no control over that's newsworthy and would get serious scrutiny put on that CA.The CA system as it is isn't good, because we have to trust so many different CAs for it to work, but if CAs were widely issuing certs to the wrong parties we'd hear about it more.
It's substantially stronger than ordinary certificate authorities without certificate pinning in many ways. (Namely, an entity out of your control (a certificate authority) being compromised / exploited / coerced doesn't also compromise you.)
The weak point is at initial connection (i.e. before you have the certificate pinned, or if the certificate changes legitimately and you have no way of confirming that fact). However, even in this case it is no worse than without pinning.
(I wish that HTTPS had a certificate-passing mechanism. I.e. if the given certificate doesn't match the pinned one you contact a site that you have the certificate for already and ask it to give you the certificate it believes is for the site. Do this for the same website with multiple sites and you'll have a good idea if someone is not trying to MITM you. You'd have to have rate limiting, etc, etc, but it would in many ways solve this problem. Unfortunately, it's something that would have to be built into the protocol, or else it would be blocked often enough to not be useful. (ICMP and firewalls, for example))
A non-plaintext connection is still more secure than a plaintext connection, so it shouldn't ever get a worse warning than a plain-text connection.
You should do the same to those certificates that you did to TURKTRUST, just throw the US CAs out.
VeriSign and GoDaddy, which the NSA frequently uses for MitM?
Link?