[cityroasted]

To be specific, what is disallowed is using technology to steal signs (the camera). You can steal signs if there is a runner on second, although the pitcher and catcher can then change signs. It's one of the 'unwritten rules' in that it happens but they try to be sneaky about it. You don't want to disrespect the other team. More often with good scouting hitters can get an advantage of the pitcher is 'tipping the pitch', i.e. using a different delivery or setup depending on what pitch is coming. For instance, how high they hold the glove