How many people replying to this even bothered to read the original post ?
Look - this is what he said :
All of the trade activity in the screenshot are not mine. I originally had $4,000 in USD but the culprit converted it to BTC and withdrew.
Come on. Not wanting to be mean, it's a shame that you've lost your money and I hope this mystery gets solved, but of course there was something you could have done, and you know it very well: you could have stored your coins yourself, offline.
This is to everyone who stores their money on Gox and others: Seriously people, Bitcoin empowers you to be your own bank. To have no counter-party risk. And you keep letting your money in bank-like institutions? What's to prevent MtGox servers to be hacked, and eventually even its cold wallet stolen like bitfloor? Or, even more likely, what if they're raided and all the money seized, à la Cyprus?
Store your bitcoins yourself.
If that sounds "too geeky" and you're not willing to go through the learning curve right now, then perhaps Bitcoin and you are not ready for each other for the moment. Interesting projects like Trezor are on development, and they could bring the two of you together again soon enough.
Again OP, don't take my post in a bad way, I am really sorry this has happened to you. But please don't claim that you haven't been warned - I'm definitely not the first one saying this -, or that there are no ways to hold Bitcoins safely, because you know that's not the case.
Well I just read the original post and what you're saying here is clearly incorrect.
The OP had $4000 in his MtGox account. Someone gained unauthorised access and purchased Bitcoin.
After purchasing the Bitcoin they withdrew it.
So he had USD sitting on the exchange - not Bitcoin.