Sign stealing has been in the sport of baseball for decades. Players used to try to decipher catcher signals that were being relayed to the pitcher. Men standing on second base would peer down the pipe and then pass that information along to the hitter in a discreet manner. First or third base coaches would try their best to break the codes as well. This information was then taken back to the dugout and spread like wildfire to a player's teammates.
With the advent of PitchCom, a device that allows catchers and pitchers to communicate pitcher and locations via radio frequencies earpiece and a controller, sign stealing had to be adapted to the modern game.