Well, that will stop you from getting teleported somewhere else (in this case, 1000m) by detecting if you've moved 1000 metres in less 3 seconds. Still that can't be done with a chopper at 280km/h. What that won't stop is from someone teleporting you 100m in the air and killing you. If I were to make that, it would be more difficult, using the Z coordinates and you'd have to make an exclusion for helicopters. It would also have to be a much shorter timer on it (using more resources) because you could probably climb a steep mountain in a vehicle.