I seem to be in the minority on Hacker News, but as someone in the professional computer security field I know that any company or state/department/organization can be hacked by a motivated attacker. In the case of SONY, the attackers were able to enter the network through spearphishing emails - something that essentially no investment in security is going to prevent. The malware similarly could not have been detected, as signatures for this specific compilation were not known.
I have a hard time blaming the victim of a cyber attack that would have been practically impossible to prevent. I agree that SONY made bad decisions with regard to its hording of unnecessary data, but also recognize that this is hardly unique to SONY and not standard advice given by security professionals (it should be).
Norms are important so that you can accuse 'groups with no morals or ethics' of doing something wrong. Norms may only discourage and not prevent behavior but without norms its difficult to find common ground for behavior that may otherwise be chalked up to 'culture' or 'tradition' or 'nature'.