It isn't hard to understand why Sony might make the change now - they want to segregate digital content between regions, they want to promote the sales of memory cards, etc. - but that wasn't my concern, really. I'm curious how the preservation of data across multiple accounts on the same memory card could have possibly been an unintended loophole or exploit. The OS asked users straight-up if they wanted to reformat their memory cards when switching accounts, and users could select "no", thereby preserving their data. That isn't a loophole, that's a feature, and a rather elementary one to be honest. Why would Sony have included that option if they truly wanted to enforce a "one card, one account" policy from the start?