It's "Subscription= Open,Confirm", not just "Confirm", and in my view
it's better than "By Owner" because it verifies a two-way mailing path
for the subscriber.
 
Naturally there are cases where you <want> to use "By Owner" and the
confirmation comes when you ask the user to sign your subscription
agreement or list charter or what have you.  If you're going to run
an Open list where you don't exercise any up-front control over who
subscribes, you should definitely use the "Open,Confirm" option.
 
Nathan