How would you like to be on the end of a civil lawsuit for libel for claiming that Mt. Gox leaked personal data, implying that they were complicit or involved with the theft? Surely you have no evidence to support this claim.
Yeah, that's a shitty thing to say, and I'm not defending Mt. Gox's lousy security practices, but I'm just pointing out how crappy your argument is by making a similarly crappy argument against it. Why? Because civil lawsuits like this are about money losses. Your libel almost surely more provably costs them more money than the monetary damages you faced by Mt. Gox, at worst, having insufficient security measures that allowed this data to be stolen easily. Even that is an uphill battle for you to prove, because they'll be compared against best industry practices rather than an impenetrable wall.
In the case that leaked hashes lead to your account being hijacked, sure, you are probably due your account balance. But if attempting to get money beyond that, any judge in the land is going to ask you first, "Why are you suing Mt. Gox for insufficient security when your own password was easily guessable?"
You can't blame your landlord alone for crappy locks if you leave the windows open. The blame is shared, as your expectation of security is diminished by your own lack of it. As for the argument that they should have had two-factor authentication, account address locks and such, well that's just like alcoholics who blame their families for not fighting the bottle from their hands. "God, why are you not stopping me from hurting myself?"
Your argument is as silly as my libel one, but have fun in the murky swamps of international law in suing for your hundred dollars. Even if you miraculously win more money than your provable monetary losses, so will everyone else as we all practically would have the same case, if it was valid. In other words, if you win, it'll be noncollectable.
Anyway, on with more armchair lawyering! Oh man I practically have a law degree, as I have this dictionary RIGHT HERE on this bookshelf behind me and it says this and this and this about force majeure that I'm going to cherry pick to support my anger. At least MagicalTux probably consulted a lawyer before making his assertion or writing his TOS.
Damn, as a level 10 armchair lawyer with action court battle pads, I have to say that practically any legal stance can be supported if you research hard enough and are allowed to choose from random crap on the internet rather than applicable laws, cases and precedents. Dude, with those crappy standards, I could churn out 10 pages easily on any outrageously wrong assertion, such as that child porn is not actually illegal, rape is a permissible act where only the woman is to blame, and black people are not due the rights of other humans. I've actually done crap like that, only not so disgusting, in opposition research papers that surely will prevent me from ever holding public office.