I wouldn't mind if all ISPs blocked viruses and worms.
AOL - One Billion Viruses Blocked in a yearhttp://news.com.com/2100%2D7349_3%2D5213116.html
America Online says it's blocked more than 1 billion virus-infected e-mails since launching a screening program in April 2003. The Internet service provider, a subsidiary of Time Warner, says it protected each of the company's subscribers from an average of 30 virus attacks. During the peak of the Sobig.F outbreak in August 2003, AOL hit its own peak--for viruses blocked in a single day: 24 million in just 24 hours. The virus led the list of the five most pervasive viruses over the last year, followed by MyDoom, Netsky.A, Netsky.D and Swen.