Which is why:

1) I use Ghostery: http://www.ghostery.com/, thanks to someone who pointed it on HN. Much appreciated! Now FaceBook's webbugs are largely blocked.

2) I log out when I leave FB.

3) I delete FB cookies regularly.

BTW, I looked for an e-mail link or "comment" feature for the author, Jeff Escalante, and couldn't find one. Instead I'd have to find him on Twitter, I guess. So much for (relative) privacy.