Messaging team-mates

Probably been proposed before, but what do you all think if Niantic could include some way to do this? I get that there would be some liability issues and might need precautions to protect younger players, but at level 32 I seem to play at different times then the other names I recognize in gyms, but would welcome the opportunity to strategize.
This might also go a long way to limit the spoofers and double account players, if it created a better team morale (since it's really non-existent AFAICS)