Thanks for your replies.

What this guy clearly did was copied it once, loaded it, and then copied his
site, so that the "Mirrored from....by HTTrack Website Copier" tag shows his
own domain name. 

It's a complete copy down to the copyright notice! He replaced my domain name
with his own. And he added his own pop-up advertising.

I've been on the net for many years, and I'm not worried. I was initially
completely alarmed by the audacity of someone to do such a thing! I apologize
for my premature post - I was in "reaction" mode. But there is such a thing as
Internet Archives. There will be no problem proving whose content it is. I
have contacted my brother-in-law, who is a lawyer, and will proceed with him
if the person who copied my site does not respond to my emails asking him to
remove the copied material promptly.

Actually, I never knew about HTTrack until I discovered the copied site and
saw the tag about mirroring. It looks like a fabulous tool. I downloaded a
copy for myself. There will always be people who abuse legitimate tools,
unfortunately, and we can't blame the tool for these types of people. 

Again, thank you for responding!