I just was made aware of this by someone on one of my wifes newsgroups.
If it applies to you by participating on a Yahoo group then you can make your choice. If it does not apply Sorry for bringing it up.
FYI:
>
> Yahoo is now using something called "Web Beacons" to track Yahoo Group
> users around the net and see what you're doing - similar to cookies.
> Take a look at their updated privacy statement:
>
> http://privacy.yahoo.com/privacy/us/pixels/details.html
>
> About half-way down the page, in the section "Outside the Yahoo!
> Network", you'll see a little "click here" link that will let you
> opt-out of their new method of snooping. I recommend doing this. Once
> you have
> clicked that link, you are opted out. Notice the "Success" message at > the top > of the next page. Be careful because on that page there is a "Cancel
> Opt- out" button that, if clicked, will *undo** the opt-out.
>
> Feel free to forward this to other groups.
Source: OS2VOICE