The lost keychain

Imagine you come home from school — and in front of the door lies a keychain. Not yours. A stranger's.

On the ring hangs a tiny note: "Berger family, Linden Lane 14, Apartment 3."

If you wanted, you could just walk in. Into a stranger's apartment. Into strange rooms. To strange things.

"I'd never do that," you think. Obviously — it's not your home.

That's exactly what a password is online. It's the key to your room: your chat, your games, your photos. Whoever has the key can walk in. And once inside, that person sees everything that belongs to you.

So it's worth taking a close look when you make your key.