If you search on "library elf" at Bloglines today - you get Error Error Error. Jeff Chow, a Library Elf developer was quick to respond to my post yesterday. It turns out that the problem is that Bloglines considers all feeds public unless the RSS feed is HTTP authenticated. (thanks also go to Jenny, Glenn and Chris). Lots of good comments on that post.
Really persistent folks can still click on Elf "error" entries in Bloglines and see frozen snapshots of what people checked out -- I don't know if those will ever go away. Significantly, the email addresses are gone.
But worse, as Jeff points out, the problem exists for other "private" RSS feeds turned public (my phrasing). Search "Seattle Public Library" in Bloglines to see more patron records (no email addresses). Some patrons may be willing to trade in some library privacy for convenience, but they should at least know what's happening. Seattle has a notice to this effect, though it makes it look like marking a feed "private" is enough.