strongly disagree (Score 1)

I run my own MTA on a dynamic IP. Acountability exists the same way accountability exists for websurfing. My ISP logs all the information to whom they lease each IP. Spammers are businesses. They are not hidding, otherwise they wouldn't be able to do business and profit! It's a legal problem not a technical one! (BTW, I receive daily relay test messages by my ISP, so running open relays does get noticed, and I am sure my ISP would have taken action!)