I also agree that a big surface area (such as units with independent web strategies all over the world) increases the likelihood of there being some breach of security. What I find embarrassing here is that we aren't talking about one of the Sony properties having a breach, it's lots and lots of them.
I suggest that this is symptomatic of a problem with Sony itself, not just the surface area they present. What I'd expect from a well-managed company with a big surface area is yes, some property might have a breach, but that would be the exception. It's beginning to look like Sony's lax security with respect to customer information is the rule and not the exception.
JM2C, I am not claiming I know this for a fact.