I'm suggesting it was something like "Your payment for iCloud didn't go through, so we locked iCloud, and whoops our system is a mess so I guess you can't use the App Store or iTunes either, maybe, although it's possible you're just getting a boilerplate error that isn't actually telling you the truth". This would be consistent with my past experiences with Apple's online services, and it's the reason I don't plan to spend money on any of them or rely on them for anything important. They're a dumpster-fire; the exact opposite of Apple's hardware and (for the most part) their system software.
Fraud detection is plausible too, though