sorry bugger writes: "From the article: "Peer-to-peer software applications are a network administrator's nightmare. In order to be able to exchange packets with their counterpart as directly as possible they use subtle tricks to punch holes in firewalls, which shouldn't actually be letting in packets from the outside world." More under http://www.heise-security.co.uk/articles/82481"
At the source of every error which is blamed on the computer you will find
at least two human errors, including the error of blaming it on the computer.