Note to Commenters
December 6: Problem resolved. Fortunately, no one's e-mail address was compromised. It is safe -- turns out it always was safe -- to include your e-mail address in your posts.
December 5: Please remove your e-mail address from future comments. That is, remove it from the box titled "Author Email."
A reader has identified what looks to me like a security breach. I've notified my host Squarespace, but until they get this fixed, I'm concerned that your e-mail identity could be compromised.
As far as I am aware, no one's ID has been compromised yet but there has been one close call.
I am almost certain this is a programmer error, not a hacking incident.
Marie
Update, December 6: This problem is ongoing. Squarespace has not deigned to respond to my multiple alarms. Their technical service used to be fair-to-middling. Now it completely sucks.