Or, if one or both parties were running the Facebook app with location services enabled, it could also have been GPS too. I wrote about this a few days ago.[0]

Or, if one or both parties were running the Facebook app with location services enabled, it could also have been GPS too. I wrote about this a few days ago.[0] Basically, new Facebook accounts that you run on the app with location services enabled will provide creepy location-based friend suggestions by default. [0] https://news.ycombinator.com/item?id=13252568 https://news.ycombinator.com/item?id=13252568