There is a big difference between hacking BITCOIN and stealing BITCOIN. One need to understand that BITCOIN can not be hacked however it can be stolen from your exchange wallet, your cloud bases wallet or any other source where the internet can reach. If you want to save your BITCOIN you can store them in hardware wallets like trezzor or ledger s. So BITCOIN can not be hacked, it can be stolen and transferred from your wallet to the hacker's wallet.