The whole idea is a privacy minefield, so it would have to be very carefully designed and implemented, of course making it opt-in. But still, should we even pursue this idea?

So that, for example, even if I met someone just briefly, they can still later see the contact information that I am willing to provide.

Wouldn't that make it much easier to connect with people who live close to you?

Are there any relevant projects or ideas that already exist?