I've noticed recently that two PGP programmers (Mr. Zimmerman and Mr. Atkins) do not seem to PGP clearsign their messages to this list. In fact, a surprisingly small percentage of messages on the C-punk list are signed. This despite the fact that the average subscriber is at least literate in PGP.
Actually, I don't PGP sign my messages because 95% of the time my connection to my mail host (the machine on which I read and respond to mail) is insecure. Composing the message, bringing the message to my local machine, running PGP, re-uploading the message, and sending it is a big deal and I don't consider it important enough for my everyday posts. When I send out notices that I consider important I do sign them. But that is fairly rare (at the moment). Basically, I refuse to type my passphrase over the net, which signing all my messages (this one included) would require. -derek