where you maybe see what the pitching coach is signaling in, or the way a catcher sets up for a certain pitch, or where the pitcher comes to set with his glove before a certain pitch; those are completely fine and absolutely a legitimate part of the game.

When you place a HD camera in Center Field, point it at the catcher giving the signs, have a staff of people decoding the sign sequence using an app, then using a blue-tooth device to signal the batter and baserunners what the next pitch is that is coming; that is a complete no-no. Ruins the game and is complete cheating.