New Spamming Tricks?

I'm wondering if there's a new trick out there for verifying email addresses, and/or adding them to spam mailing lists. In going through my list of accounts on various servers around the Net, to weed the chafe from the wheat, I signed into Topica.

Topica is an email list directory, much like Yahoo Groups! Yahoo! Groups allows you to customize your account to say that no one may add you to another mailing list without your approval. I'm not sure if Topica has a similar precaution as, after I logged in today, I discovered I was on far more than the four lists I recognized (EGR, Finkydoodle, joho, and eeggs.com).

I'm pretty positive I didn't sign up "California Premier Attorneys 1", "Corporate Counsel 1", "Enlarge Today", "Great Offers", "Miscellany", "new", "Open Letter", "Web Services", or "WI_Pulse_20020311". Even more interesting are that all of those lists have zero messages sent (or archived).

Are they waiting for me to say "well, who the frel are these people?" and unsubscribe? The act of unsubscribing, presumably, would send them an announcement that "morbus@disobey.com" has been removed, thus confirming my existence.