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Someone asked for a cite on the Consumer Reports claims in my Black Hat 2008 slides. I went and tracked this down, and I actually picked this up from the Meandering Wildly blog. Looks like I misread this a bit — a previous dataset had come from Consumer Reports, but the data in my Black Hat deck actually came from Venafi, a security firm that specializes in systems management. Some collateral with more of their SSL data is here. Their methodology for collecting the data, according to Meandering Wildly:
It’s a phone poll, so it’s subject to standard errors of self-reporting, and their margin of error (2.5%) is given for a 0.1 confidence interval, which is a little slack for my tastes, but they have a large (N>1000), US-Census-representative sample, which maybe gives us intellectual permission enough to keep playing.
Of course, I also spoke about the one case we have hard data on — when the New Zealand bank’s cert went bad, and 99% of people didn’t care. Information on that case can be found here. I do wonder how these numbers might be changing in light of IE8 and FF3’s dramatically improved invalid SSL certificate experiences.
In general, anything I claim, I’m only too happy to back up, so if you have any questions regarding any of the details from a talk I’ve given, don’t hesitate to ask.
Dan Kaminsky's Blog 
> I do wonder how these numbers might be changing in light of IE8 and FF3’s dramatically improved invalid SSL certificate experiences.
Wow, I’m at a loss to figure out how you can call it an improvement that FF3 and IE8 slander perfectly valid certs with whines about them being “invalid”. FF3 and IE8 do this solely because the users of those certs haven’t paid the tax for an entirely meaningless signature from a default root. The only vetting done by the default roots (even the EV scam participants) is “did the check clear?”
An improvement would be if FF3 and IE8 would not slander, but would instead follow and build upon the model that works so well for SSH. Recognizing certs that don’t chain to a default root and remembering the cert and non-default root for the future would be a big step forward, allowing FF3 and IE8 to achieve rough parity with the real-world practical security in SSH.
FF3 and IE8 could go a bit further with their default roots, though. Prioritizing a “check cleared” signature over a non-default one would continue to give those who persistently confuse identity with security/safety the modicum of assurance they enjoy now.
In either case, FF3 and IE8 would warn when a cert changed roots, or downgraded from a root that provides the “check cleared” assurance to one that doesn’t. This would give users useful real world security, as opposed to scary warnings that inhibit use to no good end.