[komali2]

I once tried out Tan-tan, China's version of Twitter. I was idly swiping away until I saw, on one girl, "you have crossed paths with her twice!" underneath which was a Baidu maps frame showing Balboa Park station.

Swiftly uninstalled.

[ArtDev]

Interesting. So it is technically possible.

[animex]

There are dating apps entirely based on this model.