Can i just get this clear.
Are you telling me that you do NOT impound TX's at shows?
IF true..it is insane
At any event in England all TX's are impounded.
They are signed in and checked that they are on the frequency you say they are.
You would be amazed how many times they are not![]
The Peg board (pins) are in the TX control and you need the frequency pin to get the TX.
It is signed out to you and you go fly. The TX is checked to be off before the pin is returned to the board and the TX re-impounded.
I would personally not fly at such an event without this imposed.

People (I hope) do not deliberately shoot someone down.
What this does is prevent the absent minded moment we are all capable off.

Paul