Sam Byford at The Verge:

Mt. Gox, once the largest Bitcoin exchange in the world, is operated from an unmarked Tokyo office block that offers no indication of its major, controversial influence on the digital currency’s health. No indication, that is, unless you’ve walked past the headquarters in the past week, where protesters are attempting to draw unwelcome attention to the company’s existence. “Mt. Gox: Where is our Money,” reads one sign. “Mt. Gox: Are you solvent?” reads another. What’s going on?
If you’re using Bitcoin as a legitamate currency, you’re an idiot.
There’s way too many unknowns surrounding it, so if you’re using it, you’re just rolling the dice.