The WEB is the WEB, NEWS is NEWS, and MAIL is MAIL: they each have their
own security/privacy attributes.

If a list has PRIVATE notebooks, then a list subscriber must register a
LISTSERV (not list) password using the standard e-mail three-way handshake.
 This most likely is as secure as someone subscribing with CONFIRM
processing on a list that has a keyword definition of REVIEW=OWNER and
lurking on the list looking for email addresses.