This is a very simple exploit but can cause much frustration for other players, unfortunately it only works best for horde players. If you are horde go on either of the boats that take alliance to northrend. There is one from SW to Valiance Keep and one from Menethil Harbour to Valgard. All you have to do is kill an alliance player on either of the boats as soon as they arrive at their destination. If the player does not reach their body in time to res and the boat leaves and they will be resurrected on the boat when it goes into the loading screen back to the previous destination. Basically they can never reach their final destination only if they spirit res or make it to the boat b4 it leaves.