The big news in the Bitcoin world today is that the website Mt. Gox — which at one point was the pre-eminent place to trade bitcoin — has now gone offline. It's just up and disappeared.

This comes a day after the company withdrew from the Bitcoin Foundation, and amid weeks of withdrawals being halted.

Bitcoin advocates are passing around the embedded document, which claims hundreds of millions of dollars worth of theft has hit the site over the years.

Here's the key part:

For several weeks MtGox customers have been affected by bitcoin withdrawal issues that compounded on themselves. Publicly, MtGox declared that “transaction malleability” caused the system to be subject to theft, and that something needed to be done by the core devs to fix it. Gox’s own workaround solution was criticized, and eventually a fix was provided by Blockchain.info. The truth, it turns out, is that the damage had already been done. At this point 744,408 BTC are missing due to malleability-related theft which went unnoticed for several years. The cold storage has been wiped out due to a leak in the hot wallet.

At current prices, these bitcoins are worth over $300 million.

And here's the full document:

MtGox Situation: Crisis Strategy Draft by twobitidiot