I just took a look at the first 10 messages I could pull down from alt.anonymous.messages using pgp2.6.2 . Eight were encrypted with symmetric encryption. One was encrypted with keyID 591B0E69. A last one identified itself as encrypted with public-key crypto, but in a format not otherwise intelligible to poor 2.6.2 . Now, keyID 591B0E69 isn't in the keyservers, of course, but it will be interesting to watch alt.anonymous.messages for the next few days and see if any other messages encrypted to that key should show up. Well, if I get around to writing the scripts to watch for it, which I probably won't. I don't suppose anyone's been gathering data like this in public? In particular, it'll be interesting to see if 591B0E69 is simply receiving an initial message (to set up a shared password for conventional encryption) -- or if it will receive many more messages. This is a good reason to use Adam Back's Stealth PGP. Although, as David Hopwood has pointed out, ordinary RSA may reveal information about the key used to encrypt, even if the headers are stripped out. There are fixes for that, of course, but not yet deployed AFAIK.