I am currently listening to Post 45 TAC and the ground units are encrypting their signal. I heard the air unit on Post 45 Dis tell the dispatcher to have the 2 ground units turn on encryption and go to the TAC. I the air unit and the one of the 2 ground units has it on, one is still in the clear. Was surprised to hear them doing this. It sounds like they are working traffic enforcement from the air by the part of the conversation I can hear from the unit in the clear.