There's a wrong concept in your question. The Bitcoin actually can't be hacked, it's too hard and difficult; what hackers do is put a trojan in some junk mail which the user open, steal all the info about the wallet (address, password, etc) and transfer to 2 or 4 accounts in order to lose tracks.

This is something very common and usually the targets are people who have a big amount of BTC in one account.