You say sign stealing; I say effective intelligence collection and reporting.
Just thought of this. When my oldest daughter was 10, she pitched fastpitch. We were in a tournament game one evening, and we only had two signs (fast ball and changeup). She was still developing her changeup, and we never knew where it was going. But, if she got it right, it was very effective has her fastball was very hard for that age to time.
Anyway, we didn't try to hide the signs. So, the 3rd base coach starts calling the changeup pitch to his batters. During the changeover, I told my daughter that we were going to flop the changeup sign.
Sure enough, first batter comes up, we get a strike, so I call for the changeup on the 2nd pitch. He yells out, "Here comes the change"!
My daughter zips a fast ball right by the batter for a strike. The batter steps back, looks at the 3rd base coach, and very plainly yelled, "STOP DOING THAT!"
I just smiled
!