Yeah, this sounds funny ;-)
But actually I get second thoughts pretty quickly on this.
1) There are plenty of services to hide your actual data in whois.
2) You do not know for sure whether you hit the right person.
A lot of spammers are affiliates that start out freshly and have no clue what they are doing. They buy programs that promise "put your ad in front of the eyes of thousands of visitors" and what in fact happens is that those programs create spam comments. If you go to the web site in the spam comment you will not hit the spammer but the product owner who will have to deal with the spam.
3) Isn't this fighting spam by creating more spam? It will severe the spam problem, and not help.
4) An eye for an eye, a tooth for a tooth. If I remember correctly that was set as law in the codex Hammurapy in ancient Babylon - our sense of justice and our law system should have evolved a bit since then.
5) It is not worth spending more than even a few seconds of my valuable time for spammers - If I instead use that time to write another article on my blog it will help my bottom line far better than the short feeling of retaliation.
Mike