What kind of proof are you looking for?
For one thing, they should publish the results of the audit they claimed was performed.
Then I would agree with you, theymos. That would be enormously helpful. Right now All I'm seeing are myself and a few vocal parties who feel wronged by this, and this statement, which I might add was not made to the public at large.
If Mybitcoin was even a third or fourth rate financial institution in the mainstream world we would expect more than what we've gotten.
My point in all this,
Mr. Williams, you owe your customers, anonymous or not, an explanation, and a way to reclaim their funds.