Minecarts, full velocity without power

If you place a Boat into a Minecart, you will be able to control it while being inside it, by using vice versa controls (ie if you press left, it will go right). If you place the entity on a rail and press the down-button, it will go up to full speed without redstone and even if you release the button it will keep going for all time until you jump out of the Boat, even without redstone.