Reading about password habits, a lot of folks actually keep written copies at home. Saw a news piece once where experts called it a physical vulnerability, but it's so common. Your dad's backup system is creative, though not exactly secure. If guests come over, those passwords are just out in the open. Kind of defeats the purpose of online security, right?
Wait, he actually taped them to the fridge for everyone to see? That’s just leaving them out for anyone walking through the kitchen. The whole point of a password is gone if it’s on public display like that.