Re: where a photograph was taken
On Android at least, the first time you use the camera on a new phone it asks you whether you want to turn ON geolocation (yes, that's right folks - it's off by default).
Assuming it's a Marshmallow or later handset, it will then ask you to confirm you want to give the camera app access to your location. So that's two steps before it stores the lat/long in the EXIF.
Even if you answered yes to both of those without meaning to, you can go into the Camera app and turn off the saving of location data.
Finally, if you share the image from the Google Photos app, there is a setting (which admittedly is off by default) which strips location data from the shared photo.
Just one last thing - they found 229 photos with location data in, out of 44 million files. It's not exactly a massive amount, is it?