One issue that I do see with Swarm City is the fact that it is a ride sharing application, meaning it is reliant on users geolocation.

I don't know much about Swarm City - My main concern is along the lines you posted above - but more to do with personal safety. The requests will be public right? We saw issues of robbery etc with Pokemon Go. What happens when you broadcast that you're at X location waiting for a ride with a smartphone in your hand? particularly if that location is a bit shady.

Also what about other concerns for instance posting that you need a ride from your house to the airport. Now people know the address of someone who wont be home.

Or just stalking type activities if someone knows your account name they can follow you right?

What about background checks for drivers. Or issues with riders causing damages? theft? insurance?

The whole thing sounds like someone just thought "Uber on Blockchain = money"