in Online system All are hackable..beacuse languages can hack any language.
but it depends of how secure your btc wallet is.
You are right everything is hack able if you are not using right precautionary steps for securing it, Now if you have not enabled any type of security on your wallet and set an easy password for it then you are asking the hacker to hack your bitcoins. Bitcoins are not hack able but yes the wallets are because private key is really hard to find.