Saying it’s the responsibility for owners to protect their stuff isn’t the same as saying the attackers aren’t responsible for any wrong doing.
I appreciate nuance is something the HN community often struggles with, so hopefully this analogy helps:
If you had £100 on your person, you’d be expected to look after that money responsibly. For example not leaving your wallet on a park bench and walking off. However even if you did the latter, that doesn’t mean it’s ok for the person who finds your wallet to keep your money.
