I made a comment, but it's *disappeared*.
Looking at an account that is left open, or has no password, is not hacking. Knowing your relative/friend's password and using it to read their private correspondence is not hacking.
Hacking is 'breaking in' to another person's account by using your technological know-how. I doubt this happens a lot in JW world..
If you leave your diary on the counter, and someone opens it and reads it, that is one thing. But if your diary is in a locked box, and they pick the lock so that they can read it, that is another. And that's the difference between taking advantage of someone who is not protecting their privacy by proper use of passwords, and hacking their account
It's wrong (of course!), but it's not illegal to read someone's email if they left it open, or don't have it password-protected. That is completely different from hacking, which I assume would be illegal in many jurisdictions.