Except that these "houses" happen to be banks, which customers have entrusted with their assets (E-mails addresses, passwords, credit card details) to keep safe

Except that these "houses" happen to be banks, which customers have entrusted with their assets (E-mails addresses, passwords, credit card details) to keep safe. Their doors should not be unlocked. While I believe Lulzsec went too far in their actions, I'd say that they were trying to prove that these companies did not go far enough in their responsibility to keep their systems safe. To continue the analogy above: The PSN-hack wasn't a bank robbery. It was a person walking into the vault, unarmed, loading everything into their vehicle of choice and leaving the scene. In other words, the bank did too little to keep the assets safe.