I would like to thank everyone for their support and understanding. It really means a lot. Having other people's money taken under my watch has made me feel just about as awful as I've ever felt in my life.
I think I should have a poll to determine how to pay the funds back. Here are the options I'm thinking:
1. Pay back over time with exchange fees.
2. Same as #1, but raise fees to expedite.
3. Sell shares of Poloniex to cover the debt; dividends paid regularly.
4. Award such shares to everyone immediately and consider that repayment.
Let me know if I'm forgetting an option here.
About recent deposits--it really wouldn't be fair to deduct deposits made after the BTC was taken. Obviously I should have posted a notice on the Balances page, but it is not difficult to make an exception for recent deposits.
I will be hiring a security programmer after this is dealt with.
I got no dog in the fight, so I'm fairly dispassionate on this. I think you should have posted 3 and 4 as a single item, and that's the way I'm gonna vote. If you do it, I would not mind a chance at buying some of those shares.
I also recommend, as Warren had posted earlier, that you start putting some of your income into an insurance fund to cover such things if they happen again.
Your honesty in this has probably saved your business, but coming as it did on the heels of the Empty Gox debacle, you are probably going to feel some pain for some time to come. I would try to sell shares at a rate twice what you lost to raise reserves against any sort of disaster. And I would do it through a third party with multisig verification.