ISP's

As mentioned so many times, why can't ISP take a real lead in this.

Letter to Bot Infected machine owner

We have noticed that you machine on the date of xyz appears to be infected by one or more viruses, causing problems on the <ISP> network. Please check you have an up to date anti virus software. We recommend (blah blah blah) but there are others available, many free. Also ensure that your operating system has all the latest patches

URL of link to ISP page with links to major OS patches.

Failure to rectify this isse will result in suspension of you account.

If you have already removed the virus(es) blah blah blah....

Everyone wins, ISP's get less traffic and possible tie ups with AV vendors, End User gets better connection speeds, and spammers get a harder time.