By trawling through his Messenger history, Mr Khanna noticed the latitude and longitude coordinates of the message locations have more than five decimal places of precision (pictured), meaning that a sender’s location is pinpointed to within three feet (one metre)
The Marauder’s Map (pictured) is a fictional map of Hogwarts School of Witchcraft and Wizardry as featured in the Harry Potter franchise. It tracks the location of every person in the grounds, shown as footprints labelled with the person’s name.
Facebooks Messenger’s app lets people send their location to friends and it defaults to sending a location with all messages