This thread was quite a read -- an interesting cold case of a mystery here... My guess is someone had access to his DropBox and stole his coins using its contents.
There's some additional conversation from what appears to be the OP here, before this thread was started:
https://gitter.im/ethereum/ethereumj?at=56ed8172ce5b0c6e7a1c0c71OP never confirmed if this address belongs to him or not:
1bdCxkNmBoa9yakqE6f5EJx6kSQdffDWR
Its an intermediary between his exchange output address and the hacker's address... doesn't sound like it was his.
The 1bd address has a lot of previous activity. For a long time it received weekly payouts from a pool associated with BTCGuild that went under in 2014.
I happened to find the private key to these coins, and Google led me to this thread.
I am unable to PM you, as the forum says you are not accepting PMs from Newbies.
Send me a message if you're still around, and we can work out a transfer to a new wallet.
Don't suppose you'd want to sign a message with the key to prove you actually have it...