I took it up with their upstream also. The rule on spam is very simple and unambiguous. If a person didn't request a commercial message, don't send it.

Chaosunlimited (the upstream) passed my e-mail to ADT, who sent me an e-mail telling me when I registered and how many posts I have made. This is completely irrelevant. Registering and posting is not a solicitation for commercial messages. There's nothing on the registration page about being added to a mailing list, and there's nothing on the entry page for posts about being added to a mailing list, so pointing out that I've registered and posted isn't a justification for sending spam.

I'm always amazed at the number of people who believe that possessing a list of e-mail addresses gives them the right to spam those addresses. Or that any sort of unrelated communication constitutes permission to send commercial e-mail.

At any rate, ADT has deactivated my account, so whatever little posting I did there is now at an end. Apparently, the solution to complaints about illegitimate activities is to stop any legitimate activities involving the complainers. Stopping the illegitimate activity doesn't seem to have been considered as an option.