...

20 % of the users who have posted digitally signed messages that are available in my news spool (international and local newsgroups and mailing lists) use PGP 5. The sample contains 545 unique e-mail addresses. YMMV.

These are very interesting results. One question: what are the groups about? Are they close in to PGP topics or far away?

A number of them are crypto related, including the OpenPGP and a German PGP users' mailing list. Perhaps someone with access to a large newsserver could grep for PGP signatures on the rec.* hierarchy?