I've done some research into the matter and here's what I found:
a) Bitstamp's bank is subjecting the company to extended KYC and Bitstamp is in turn asking customers for the necessary data.
e) Bitstamp is undergoing financial difficulties, maybe connected with the recent downward swing in prices (they overextended themselves? They fractional-reserve'd customer money without telling anyone and now they can't make ends meet anymore?), and they're hiding between KYC/AML to buy time.
"a" cannot be true when we are talking about BTC, only possibly true when it is fiat.
Bitstamp deposits fiat on their Unicredit bank account, not BTC. And Unicredit, like every regulated financial institution, is going to subject their customers to KYC. Every company banking with anyone has to go through it.