There is a huge difference between historical "sign-stealing" in baseball and using technology and cheating as part of your regular business. If you can't understand that, I can't help you.
- A guy on 2nd base can see the sign flashed and see the pitch type. If he figures that out and flashes a signal to the batter somehow, that is just regular gamesmanship, and it impacts one at bat. That is on the pitcher/catcher to alter their sign system.
- A smart bench coach can watch the 3rd base coach and maybe figure out what the signs are, and alert his defense to a bunt or steal. That is on the 3rd base coach to have multiple triggers and wipe-off signs for the team, and change it up periodically. This is also fine.
Having a camera trained on the pitcher/catcher on every pitch, and a monitor in the dugout/tunnel, with a system to communicate every pitch to the batter is way across the line. Any baseball fan can see that compromises the integrity of the game.