According to an internal source, the online payment company Paypal today initiated a mass chargeback on "thousands" of Sony Entertainment Network transactions, for reasons yet-unknown. Because these transactions were charged back it has ended up putting the PSN accounts affected into debt, which triggers the system to auto-ban that account until it's back in the black.
Sony is apparently speaking with Paypal in order to work out what has caused this problem and fix it, we've contacted both for comment, but at the minute this is all the information available.
http://www.kotaku.co.uk/2017/06/29/psa-paypal-just-did-a-mass-chargeback-on-psn-transactions
Plot thickens
Just saw this on the Kotaku page in the comments.
Just off the phone with PayPal. They have advised that this error is on Sonys end and is to do with them closing or somehow limited their GDP account, meaning that the funds didn't credit the accounts.