You wouldn't want to share a location with every message, but rather give users the "choice" to share location for any given message they post. If they've just

You wouldn't want to share a location with every message, but rather give users the "choice" to share location for any given message they post. If they've just seen an accident, they'll want to post a URL. If they're at home, not likely. You might even ask users to "mark" private locations from which location can't be sent, like school, home, or work. You could also allow the user to vary the accuracy of the position by zooming in/out, to give them control of proximity for their posted locations.