Canter & Siegel posted a few thousand spams (the famous green card spams), probably helped by someone with imagination and technical skill. Long and tiresome threads discussing the legality, morality and all other aspects of this resulted. Canter & Siegel then tried again on a different subject, this time without able help.
On the same evening, my friend Chris Owen posted a 300-line diatribe, rebutting something or other point by point. I clicked. I just couldn't bear to read it, and decided: It's time to stop discussing this and do something.
A few minutes later, I had posted Usenet cmsg cancel messages for a few spam messages, bearing my full name and address in the body text, something like
This cancel posted by Arnt Gulbrandsen, <street address at the time>, Trondheim, Norway. Sue me if you want. That's all it was. At least one of the postings had a syntax error and was not even an effective cancel.
My actions were important (only) because I was the first person to stand up and cancel spam, and the reaction showed that people generally thought cancelling spam was ok. That's all. I was surprised by all the hoopla. I really don't think it justified a front page story in the New York Times. Nice picture of me though.
Shortly later, someone else asked whether I might provide a facility for him to post anonymous cancels. I did so, and s/he started cancelling spam under the name Cancelmoose. Many people thought that was me, but it wasn't. All I did was relay postings and promise anonymity.