Here are a couple of recent news stories about real revenue loss for once. The question is, everyone tends to know who is responsible for counting the cost of security and the equipment that needs to be replaced, but is somebody keeping a tally of the loss of revenues? Not being able to provide a service or giving customers credits because of missed SLAs is the kind of revenue loss that often gets ignored.
http://www.theregister.co.uk/2006/11/01/level3_robbery/
http://www.theregister.co.uk/2006/10/23/vodafone_network_outage/