The presumption should always be that you don't invest what you can't afford to lose. That way if things go horribly wrong, as in Mt Gox, you won't go to the poor house because of that risk. At the same time its ridiculous to assume that he would put himself in a worse position then that. The best he can be expected to do is chart a course where the site can continue to operate and avoid future errors to the extent possible. The most frequent option is to just give up and give people back a percentage, as suggested. Its the most frequent because its the easiest. ..it also is the least productive for everyone involved, leaving the only winner in this to be the hacker. ..thats what should not happen.
Raising the fees to 1.5% would mean that the users would be paying for this mistake. It doesn't make sense - take 12% of balances and then get the users to pay for it with higher fees. If fees went up many would go elsewhere, leaving the rest of us to pay even more. The users should not pay for this.
will continue trading now here (with a smaller budget though)