I found the spamcop site and their bulletin board and posted a rather more incandescent version of the above, and have had two replies, one reasonably conciliatory (probably more so than I deserved) by email, explaining their set up and basically saying write to yahoo. I wanted to reply to that to say thank-you but couldn't because my email was bounced back by spamcop.

The other was considerably less helpful, just saying we provide the information, what other people choose to do with it is nothing to do with us, and that it's my fault anyway for not using a decent service provider.

I did try writing to yahoo, but just got a form letter back.

Bingley

Bingley