Rather Large Mistake (Score 2)

I just sent an email to the people at Alchemy Mindworks about this page. Here it is:

Hi, I just read your Death to Spam page (after following the link from Slashdot, if you're interested), and I have just one comment to make: you recommend replying to some spam with polite messages, or even veiled threats, however, this is just about the WORST thing you could possibly do after receiving spam! Nearly all serious spammers have software which generates custom email for each user, usually with a url in it. When you reply to that email, or visit that url, it personally identifies that your account is active, and the spammer will then most likely sell that information, along with the addresses of thousands of other active accounts that they harvest in this way. Replying to spam will only make the problem worse.

Any comments on this comment?