This is the oldest trick, pulled out by all scammers since the very first bitcoin scam: the
MyBitcoin eWallet.
1) Stop withdrawals
2) Take the service down and announce it was hacked and all the bitcoins are gone
3) Rage spreads amongs customers, later on despair takes over and finally customers settle in the acceptance phase
4) Suddenly announce that a portion of the coins were recovered (in the case of MyBitcoin, 49%; in the case of MtGox, 25%)
5) Customers are happily surprised as they thought it was all gone, and gladly accept the partial refund
6) Minimize legal actions & profit.
(wash, rinse and repeat)