Furthermore, by gathering a couple weeks’ worth of chat data on the map and looking at the location clusters you can even figure out his weekly schedule.
You can now see the fun (and slightly creepy) things this data allows you to do. One day when I was chatting frequently with a friend of mine (@tomasreimers) the map allowed me to track his hour by hour locations.
The power of defaults on human behavior is well documented in psychology and suggests that few people will put in the effort to deviate from the default action of sharing.
Furthermore, because there are no readily visible consequences to sharing your location, users are never incentivized to devote attention to what this default of sharing is actually revealing about them.
However, I didn't realize how much data about me Messenger was revealing to the people I chatted with until last week when I began tinkering with my message history.
As you may know, when you send a message from the Messenger app there is an option to send your location with it.