BTW, very often we shoot ourselves down.

We had a case of that recently.
A newbie walked onto the field with his "anyone can fly it RTF/ARF" and threw it into the air. Flew around a bit and WHAM, straight in. Turned out somebody had turned on in the pits.

Turned out the guy in the pits had been flying all morning.
Turned out the guy in the pits had the frequency pin and had it from before he'd turned on the first time that morning.