Friends,
One of our online friends PM'd me about this subject, and the fact that I occasionally show my teenaged daughter what people are doing that the general public is completely oblivious of, but switched on street cops/detectives/narcs see on a regular basis both on and off duty. Guys see it when they go to the grocery store, in parking lots, wherever.
Anyways, he asked that a thread be started about this subject. I will drop back in and contribute after a bit. I have some family stuff to attend to right now. Minions to get bathed and in bed, all the usual stuff.
Lots of experience here, so have at it.
Cheers!