But these are public photos offered by facebook under that license. Anyone visiting the profile will have a copy of said public photo in there cache. That in

But these are public photos offered by facebook under that license. Anyone visiting the profile will have a copy of said public photo in there cache. That in itself doesn't trigger a copyright act because the photo is licensed for that act. Reusing the image would trigger copyright protections as the licease granted to facebook doesn't cover that. It would be the same as downloading a trial program with images. You can use them in the game, you can make calculations on those images (they are this big, they are classifed as tree, face, etc) but you can't include them in your game.