From Dane 101:
The University of Wisconsin-Madison Division of Information Technology (DoIT) has hooked up a webserver to the internet and issued a general challenge for people to hack it in an attempt to prove that Mac OS X is a fairly secure operating system.
The challenge comes as a response to another contest reported on by ZDNet in which a Swedish Mac enthusiast held a similar contest albeit with some significant differences that ended after 30 minutes because someone was able to hack into the box.
At the time this post was written no one had yet been able to hack into the machine.
Update 3/9/06:
According to a Wisconsin Technology Network article, “Dave Schroeder, senior Apple system engineer for the UW-Madison Division of Information Technology, said that of over half a million web site hits and 4,000 login attempts during his public test yesterday, not a one was able to scratch his Mac’s security.”