[Zope] defacement/crack statistics

Does anyone have any statistics on how often zope servers tend to get cracked? I have been looking on line and so far I have found no data on that. Either there has not been one which is unlikely or they are extremely rare which is more likely considering the ACL system. Need some information for customers and these kinds of numbers would be very useful. Thanks Designing the webpages of tomorrow http://webme-eng.com Designing the MMORPGS of tomorrow http://worldforge.org