The password to Bob's computer is very complex and changes every month, so no hacker or thief could ever get inside. Unfortunately, Bob himself can't even get in, since he forgot this month's password.
Subverted: Alice tries something obvious, but finds it doesn't work.
Zig Zagged: Alice tries "Charlie", which doesn't work. The password reminder says the password is "Charlie1", so Alice tries that, which doesn't work. The actual password is "CharlieOne".
Bob has a strong password.
The strength of Bob's password is never shown or mentioned.
Enforced: "We have to show that Bob doesn't take security seriously."
Lampshaded: "Why does Bob bother with a password if he's going to make it that obvious?"
Invoked: After forgetting his passwords dozens of times, Bob is encouraged to choose something easy that he might remember.
Exploited: Because of his horrible passwords, it's easy to hack Bob's computer and abuse the sensitive information one can find there.
Bob understands that choosing a strong password is vital for security and chooses a strong password.
Bob's computer can distinguish between weak and strong passwords, and forces Bob to choose a strong password.
Discussed: "Bob never was good at remembering things... it's probably something real easy."
Implied: Alice managed to hack Bob's computer and tells her hacker friend Daniel that she did it with ease because Bob didn't seem to take security seriously.
Deconstructed: The password's simple for a reason; it activates a trap.
Reconstructed: But the trap can be disabled with an equally simple password.
Played For Laughs: Bob switches passwords constantly, but everyone always manages to guess them. Not that it matters anyway, as all his "secret" documents only contain well-known info.
Played For Drama:
The bad passwords are supposed to protect someone's confidential information. Bob's use of obvious passwords shows how little he cares about others' sensitive information.
Alice accesses Bob's sensitive information and uses it to make his life a nightmare. Bob constantly blames himself for his misfortune because everything could have been avoided if he didn't choose the awful password.
Alice tries "ILoveAlice", which works. It turns out that Bob's girlfriend is also named Alice.
Alice accesses Bob's profile and secret documents folder with ease, but finds a folder of recipes whose password she can't guess ansd assumes to be strong... but the password turns out to be "Fido", the name of Bob's dog.
The password hint says "The password is not 'Bob'". It's true, and the password is actually strong.