As far as "beacons" what if one has more than one browser installed? Which one is used to retrieve the beacon associated image?
What if all browsers are closed (off)? What if more than one browser is open?
I understand how programs like BitTorrents work - they download via a browser that must be running at the same time as BitTorrents. But is this to say that when we open a mail program like MSFT Outlook Express or Entourage that pics are being downloaded via a Web Browser? That seems very unlikely to me.
This "beacon" thing seems to be more applicable to opening mail via a web browser, i.e. webmail.
Also, read here
Cookies, Web Beacons, and Your Privacy
and it seems that EBAY's use of cookies and web beacons is limited to on site - not via emails.
The general internet policy is that "When making use of user-profiling technologies such as cookies, log files, and Web beacons, you must notify users in your privacy statement." EBAY's privacy policy
eBay Privacy Policy
refers back to the above "Cookies, Web Beacons, and Your Privacy" link and according to that page, web beacons are placed on the site, not in emails.
What this means, I think, is that paranoia about cookies and web beacons should be directed to your browser, not your emails (unless, I suppose, you open your emails using your browser).
What someone should do is write to EBAY and ask, "I read your Cookies, Web Beacons, and Your Privacy statement and I want to know, do you place Web Beacons in emails you send me or only on your website?"