With thanks to Vlad, who forwarded this to me.
Apprarently, this nefarious practice is not unique to Yahoo Groups.
My apologies to those of you who happen to receive duplicate or multiple copies.
TNT
Sent: Sunday, March 31, 2002 9:01 PM
Subject: [24] MORE Yahoo madness!!!!!
> If you subscribe to a Yahoo group:
> Very important information about Web "Beacons" Bugs (the real name) and
> Yahoo PRIVACY Policy. (This is not directed towards email Ygroups-this
> is
> has to do with your Yahoo ID and personal info.)
>
> On the web site you will see in the privacy statement a reference to
> "Web Beacons" you need to click on the OPT-OUT
> button to opt-out. If you don't Yahoo will follow you around on the
> Internet tracking the sites you visit and every thing you do
> and sends this info back to Yahoo for "marketing" info. This is a Web
> Bug. It is not cool and it is an invasion of your privacy,
> but it is still legal.
>
> All Yahoo HTML email that you receive also includes a Web Beacon (Web
> Bug) this is so they can keep track of live email
> addy's and to see who is opening up the email. All Commercial and HTML
> email you receive has a web bug, not just that from
> Yahoo.
>
> Here is the direct link to the Web Bug (Beacon) information. You will
> have to click on the opt-out link to set the opt-out option
> which is just another cookie. So if you delete your cookies you will
> have to go and opt-out again.
>
> http://privacy.yahoo.com/privacy/us/pixels/details.html