What is the ruling on spamming and hacking websites, especially if they are for credit cards and Western accounts, and not Arab or Muslim ones?

It is impermissible to seize the funds of others using credit cards and accounts, even if they are non-Muslims, unless they are at war with Islam. Similarly, hacking websites, even those of non-Muslims, is forbidden unless they are combatants or if the sites are used to propagate atheism and vice. In such cases, it is permissible to hack them for the purpose of destroying them.