How much do worms and virus cost ISPs?

Of course, I'm certain Sandvine is selling something to solve the problem, but it is still a very nice article with some measurable numbers. http://www.globeandmail.com/servlet/story/RTGAM.20040303.gtsandmar2/BNStory/... "On any given day," its white paper concluded, "between 2 and 12 per cent of all Internet traffic moving across service provider networks is malicious. Even on well-run networks with dedicated security departments, malicious traffic constitutes, on average, 5 per cent of all data throughput." Service provider with about 100,000 subscribers will lose almost $60,000 in avoidable fees. A provider with one million subscribers will pay an additional $350,000.