One of my games in high school, our coach (a noted catching guru) noticed their catcher rose up to throw when we tried to steal. The ump was crouched, looking over the catcher's shoulder.
We couldn't touch their pitcher and our guy was on, too. It was 0-0 in the sixth. We got a leadoff HBP. Coach ordered the runner to fake steal on every pitch. The catcher rose up to throw, thus blocking the umpire's view. If you don't see it, it's a ball. It's in "the book."
Pitcher was throwing 90 mph heat right down the middle and they were called balls because the catcher was blocking the ump. He walked two more and was so flustered that he walked the next guy, too, despite us not fake stealing anymore. Walked in a run and we won, 1-0.
After the game, the other coach calmly walked over to our coach and asked him if he could take a couple of minutes to explain to his catcher what he was doing wrong that caused all of those pitches to be balls. It's in "the book."