The episode Porygon the Shapeshifting American made Porygon banned from ever being on television again. It is considered the most infamous from Japan for sending 300 children to the hospital. It was downright dangerous for them neglecting a scene that had three colors flashing hundred times in two seconds. Jwittz showed in slow motion if you want an accurate count.

I heard that problem was fixed by 4kids and they even dubbed that episode but due to that infamous moment they are never allowed to show it.