It's Not Their Fault
I've corresponded with Rick Klau at Feedburner and he's explained what happened. He merely quoted numbers that were already available publicly through the Feedburner Awareness API - something I had turned on months ago when I was playing with the feed count badges. I didn't realize having that on made the information public, even though Kevin Rose had shown me the "secret" URL that reveals the information a few weeks ago. I should have been paying more attention. (The Feedburner blog clarifies this API - worth reading for publishers using FB.)
Some good has come of this. Feedburner has wisely changed its policy about publicly commenting on feed numbers. And I've realized the problems inherent in passing my feeds through a third party.
They seem like nice guys, however, and genuinely pained by the situation. I'm sorry that I cast aspersions their way. I wish them all the best. It's a good service and I appreciate the help it provided getting my podcasts off the ground.