All I know that blockchain is unhackable but not bitcoin. I've read many stories on how people lost their bitcoin by getting hacked using phishing on their online wallets and there's also reports that the old versions of electrum are prone to hack so it's not really secure.
why not? anything on the internet can be tampered or manipulated. even blockchain doesnt have exemption to it but the chances are verry low because we all know that blockchain is like the central nervouse system of bitcoin , bitcoin cant work or operate if there is no blockchain , that is why the security that is implemented in blockchain is verry strong that even the greatest hackers such as anoymous or vendetta cant possibly hacked it.