They communicate instantaneously. The carrier (photon, electron, particle, etc) is entangled to another carrier, we measure the spin of one knowing it is entangled with the other (multiple times) and determine the states of each knowing that both will have opposite states when entangled.
Respectfully, I disagree. You would have to meet physically with person(s). Trackable by follower or device
You would have to call them. No problem, all calls are recorded and able to be replayed
You would send a letter(s). Trackable back to Lady Gogo
Forgot to mention that this could be a BROADCAST, not going to a specific person but to a group or multiple people.