It’s just that the analogy breaks down a bit. It’s fair to say a dropped wallet in a city is a one-shot game—it’s reasonable to expect neither the participants nor their acquaintances will ever encounter each other again; whereas a security vulnerability is closer to a repeated one—it’s a fairly small world. (Some kind of neighbourly behaviour would work better here, but then again, it’s more difficult to find a universal experience of that kind.) I didn’t misunderstand this, but perhaps GP did?..