However this raise an interesting topic:
How to securely verify that a device is indeed nearby and not spoofing it?
You can spoof your GPS coordinates easily on Android at least.
Your location should not be an identifying value but more or less a topic.
Being able to set your parameters to some location somewhere and chat with "random people" there seems like a feature, not a bug.
Hmm, the same reason you wanna keep your conversations private?
I can think of few cases, like if you want to giving nearby people coupons, I mean really nearby, not random guy on the other side of the planet trying to re-sell your coupons.
How to use a non-hackish, non-intrusive way to make content exclusive to local users?
Providing an ad-hoc wifi is not the solution because people may need public Internet activities and a device can connect only to one access point at a time.
On WeChat it happens that if you send a message to a 'nearby pretty girl', you get a link to some dodgy website back.
And before you call people who would send a message to a 'nearby pretty girl' naive. WeChat is in fact used a lot for hooking up with strangers.
I would expect people hooking up nearby would identify themselves a little specifically - I'd be "the guy in the tux with the red carnation". A spammer from across the globe isn't going identify themselves with a description fitting the woman in the table over. I mean, she would be "blue and white scarf" rather than "nearby pretty girl" (unless it's a spammer, yeah).
We're more focusing on allowing people to join chatrooms which the location information are to help people easily find them, there's also an invitation feature to let you tweet your room and people can join all over the world.
Yeah?
EDIT: typo.