The difficulty with legislation is that the spam/e-mail virus problem is global - the e-mail may be sent in China and come to you via a relay in Burkina Faso. You could say that it's the ISPs problem and they should block it, but should they really decide what e-mail you do or do not receive? What is their role? If they should scan it, should the post office censor your post? There's no quick-fix that I can see.