According to a redditor,
"
- It's not IP address. Facebook successfully identified a number of specific locations (bars, theaters, etc) even though I had uploaded the photos from my home
- It's not geo-tagging. All of my photos were taken with a camera that does not geo-tag (Nikon d700).
- It's not contextual tagging. There were no people tagged in the photos, no comments in a lot of them, no words or phrases or names in the captions that could have given clues
- It's not image recognition. One set of photos was taken at Cafe du Nord in SF, CA and every single shot was of the performer onstage, with no identifying characteristics or clues to be had.
"
I would really like to know as this is very interesting and none of the reddit comments (as of now, 12 hours after submission) really answer this question. What technology or methods are they using to suggest (accurate?) locations where pictures have been taken from?
Even more strangely, I have never used my mobile phone with Facebook, but when I uploaded a photo just now of a place from my childhood to which I haven't ever been since using Facebook, Facebook correctly suggested the location.
What the heck?!