SE can quite easily figure out who made those screenshots. The person who made them neglected to blur out the Minimap and the in-game clock (They didn't have it set to the timelocked game clock, it's the actual time). So technically SE can, like Blizzard has done before with their NDA breachers in Beta's past, use the information (Location on map + Time) to find out exactly who was at that location at that time. I'd guess they either a) don't know about this (which would surprise me), b) they don't want to go all-out tracking down NDA breachers, or c) they have their servers set up somehow so that they are not able to backtrack and see who was at a specific location at a specific time.