> One reason for the absence of reported z/VM system penetrations may be > that it is not a target of choice for black-hat hackers. This follows > from the argument that there may be far fewer reports of successful > attacks on the Mac OS because the Microsoft OS market share is so much > greater than theirs, and therefore a much bigger, desirable, and availble > target.
I'm not so sure this is really comparable. Certainly in the course of observing the operation of the LCDS system, there are a fair number of assaults by moderately sophisticated attackers, and z/VM has survived every one of them intact.
