No, but a few years ago I looked at all the certs in IE and Netscape and found that about 30% of them were from companies that were at that time no longer in existence. The expiries on those where-are-they-now certs were often as not three decades into the future.
N.B., if you are willing to take "no longer baked into the browser" as effectively revocation, there is a retrospective clerical job that might be a fun project if you had some graduate student labor to assign. --dan --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to majord...@metzdowd.com