Seen here: http://www.dslreports.com/forum/remark,7740720~root=security,1~mode=flat and that link points to this: http://www.crn.com/sections/BreakingNews/breakingnews.asp?ArticleID=44033 Some quotes from the second link: Microsoft has made a big deal out of asserting that Linux is not fit for the enterprise. But Microsoft itself is using Linux to help protect its servers against denial-of-service attacks. According to a post on the Netcraft Web site, Microsoft changed its DNS settings on Friday so that requests for www.microsoft.com no longer resolve to machines on Microsoft's own network, but instead are handled by the Akamai caching system, which runs Linux. Akamai runs a service to help boost Web site performance by caching copies of Web sites on many servers in many locations. Akamai can help defend against denial-of-service attacks by spreading the attack among many servers. Just as a distributed denial-of-service attack enlists large numbers of systems to attack a single server, Akamai presents a distributed defense against denial-of-service attacks.