Unlike your misfortune, no BTC was actually withdrawn from our account. 2 Billion CENT was sold for LTC, then our ZET was sold for BTC. The LTC balance was sold for BTC, all ending with a very large and expensive NMC purchase. Then finally NMC was sold for BTC for a VERY TINY fraction of the worth of the rest of the coins. The end result is our entire balances of alt coins and btc were essentially wiped out. No withdrawals were made at all.
Wow, that's a pretty unusual way to steal one's coins. That's the only way I can think right now that would actually enable to deplete account's balance without needing to access its email address, which shows that having a secure email address won't always save you.
I think it's a shame that there is no option to require 2FA for every withdrawal and every trade that I make.