FTX has been "hacked", yeah. Just as MtGox, KuCoin, Coinbene, Bitfinex etc.

From Coindesk:
On Twitter, members of the cryptocurrency community quickly began to speculate that the outflows could have been coordinated by a member of Bankman-Frieds inner circle, pointing out that the simultaneous and sophisticated hacks of FTX and FTX US are indicative of a potential inside job.
That's what happened, and that's what it reasonable to believe it happened. They filed bankruptcy for losing billions of users' assets, and a soon afterwards they announced they've had been hacked, both FTX and FTX.us? And it's still unclear to them of what happened? I don't buy it.
[...]
Time for: "Recent events should make you withdraw all your coins to your own wallet: Part 4".
