Google Chrome extension lets you to watch and track your Facebook friends
THE Marauder's Map looked like fun in Harry Potter – but in real-life its exceedingly creepy.

I can still track their locations extremely accurately from the messages they send to the group
A new Google Chrome browser extension trawls this data and lets you track your friend's movements.
The free browser plug-in uses GPS data to let you stalk your Facebook contacts – showing their precise movements on a map.
"Creepily track your friends from FB messages," the app listing promises in the Google Chrome WebStore.

The developer behind the app claims the Marauder's Map extension can also track the movements of people you are not friends with – provided you have one Facebook Group in common.

"However, I can still track their locations extremely accurately from the messages they send to the group."
Whether people will install the extension to double-check on the whereabouts of their friends remains to be seen.
However, upon installation the app does warn: "this extension was developed as a demonstration not an actual tool to creep on your Facebook acquaintances".