Appreciate the detective work. Assuming you are correct, what should bitstamp do about it?
That's for them and their lawyers to decide. We all would appreciate some public statement from them however in regards to whatever decision they take. They were emailed yesterday and have not yet responded.
I don't think there is much that can be done. Those coins are lost. It's best to move on and learn that keeping large sums of BTC in online wallets, exchanges, etc is a bad idea.