Why are they being named by the bank?
"On the advice of the police and security services, the Treasury has instructed the Bank of England to issue notices to effect a freeze of the assets of a number of individuals arrested in yesterday's operations," a Treasury statement said."
Legalities , it seems.
There is a pdf document as well that may have a bit more info. I think it is part of the legislation approved there not so long ago.
http://www.bankofengland.co.uk/publications/financialsanctions/sanctions060811.pdf