One way to protect yourself is what I've had to start doing now.  If you
look at the headers (and my .signature), you'll note that I'm sending
this with a forged From: address.  Here's why:

To see what happened, I forced myself not to generate any output at
all (no USENET postings, no mailing list items) for about two months.
Everything quieted down, and I was receiving no email ads at all.
Then, I started posting to USENET with a fake address.  No problem.
Great!  I figured I had the problem licked, and relaxed.  Then, I made
the mistake of sending two mail items to current-users@netbsd.org, and
wham! in came the ads for porno web sites and sex telephones.

Now, I make sure that _NOTHING_ leaves my site with a reply address
it's possible to reply to.  This is just a temporary measure, though:
my real goal is to set up a filtering system for incoming mail, where
nothing is accepted unless it's from a mailing list I subscribe to or
from a person I've listed as OK.  Everything else will be silently
ditched.

I'd be off the net altogether, except that there are certain software
packages I _want_ to track, such as NetBSD, PostgreSQL, Kerberos, The
Scheme Shell, Amanda and a few others.  I've been using the net for
over a decade, and it's sad to see it go to pot, but it's happening.
We desperately need some other channel for what we used to use the net
for, such as these mailing lists.

-tih
-- 
The illegal address in the From: field is a last ditch attempt at being
able to participate on USENET and on mailing lists in spite of all the
shit-for-brains bastards who make a living selling garbage to morons.
May those who abuse email for marketing suffer slow and painful deaths!