At this point there are only two types of companies in Japan: the ones that have been hacked, and the ones that just don’t know it yet.

This statement is probably very true. I think the only solution is to keep sensitive information offline. Yes, there is an efficiency cost but that is a balance that has to be struck which many companies have never fully considered. It's human nature to quickly go after the percieved benefits of new technology without fully appreciating the dangers until its too late. Case in point, nuclear power, deep sea oil drilling and so on.