PCWorld: "As security breaches explode and law enforcement struggles to keep up, some organizations are taking the law into their own
hands and punishing hackers themselves.
Striking back at hackers with, for example, denial of service attacks is a sensitive subject, since doing so is illegal in most
countries. The process involves bombarding a server with so much traffic that it crashes. However, security experts say the U.S.
Department of Defense has done it. Also, private companies use special firewalls and other counteroffensive programs to
automatically strike back at hackers, says U.K. Internet security consultant and ex-hacker Mathew Bevan and others.
California ISP Conxion acknowledges having reversed a denial of service attack on a group of hackers."