It's kind of sad to me that this even needs to be written out, it should be obvious: If you can't trust somebody, you have to break any financial transaction with that person into little pieces.

To be fair, I'm guessing most people burned by MtGox in a big way were day trading, where this advice won't work.

This is part of the reason I never day traded bitcoin- The counterparty risk is (and clearly was) too great.