Quoting Michael Paoli (Michael.Paoli@cal.berkeley.edu):
Basic idea is if one is subscribed to BALUG-Talk and/or BALUG-Admin, but not BALUG-Announce, one gets subscribed to BALUG-announce ... but there's also an exception process if one really doesn't want that.
I continue to think this is a blunder.
Autosubscribing people to mailing lists is going to get BALUG in trouble, one day. It[1] is widely considered an egregious violation of netiquette and gets domains on DNS blocklists.
[1] 'It' meaning subscribing anyone to an MLM without the standard three-way confirmation process or close equivalent.