Clasp and Warren

Clasp went first, jingling her key-ring. "The most important thing is the lock. Right now, anyone who guesses your password could walk straight in — so make your key strong: a long passphrase, three or four random words, impossible to guess. Then add the second lock — two-step — so even a copied key won't open the door." She snapped a satisfying clasp shut. "There. Now no stranger can get in at all. That's the whole of safety." The student felt safer — the door was strong now. But she frowned. Her friends were inside the clubhouse, invited and welcome — and some things she'd posted, she suddenly realized, she didn't want all of them to see, even the ones she'd let in. The lock did nothing about that.

Warren had been sitting quietly at the gate, and now he spoke. "Clasp's lock is exactly right — it keeps strangers out. But look: you've invited people in. And a lock says nothing about what your guests see once they're through the door. That's my half — the guest-list." He drew his three rings. "Even among the people you let in, you choose. This drawing — sure, everyone in the club. But where you live, your school, your weekend plans — those stay in the inner ring, for the few you trust most. Privacy settings are your guest-list. The lock keeps strangers out; the guest-list decides what your guests can see." The student's eyes widened — because now she saw the gap each of them, alone, had left.

So they showed her the whole of it, and named why one is never enough. "Watch what a lock alone does," Clasp said. "Strangers can't get in — but every friend you did invite sees everything, even the private things. There's the gap a lock can't close." "And a guest-list alone," said Warren, "means you've carefully sorted who sees what — but the door's wide open, so a stranger can wander in and ignore your whole list. There's that gap." The student understood: they weren't two versions of the same advice. They were two different protections, each covering exactly the hole the other left. "The lock is who can get in at all," said Clasp. "The guest-list is what the ones inside can see," said Warren. "You need both."