[lucaspiller]

I'm guessing it's advertising / marketing related. Maybe they aren't doing anything yet with the data, but I'm sure the terms and conditions allow them to do whatever they want with it in the future. Being able to stalk your friends is how they make people willing to give them the data.

[kosei]

Here's the thing, though: they absolutely could do that without the user knowing (I'm sure plenty of companies do). By showing the location information to everyone, it makes this much more readily apparent to users and gives individual users way more information than is necessary. If Facebook wanted to get your location data through Messenger, they absolutely could do that fairly easily without notifying all of your friends of your whereabouts with every message.

Honestly, and maybe I'm in the minority, showing that information readily to my friends is MORE of a red flag than if Facebook solely had that data. Because let's be honest... they already have that data from my usage on the FB app (albeit at a lower frequency).