There was an episode of The Outer Limits (7x08 Think Like a Dinosaur) that dealt with this exact question.

In that episode, humans are maybe-given a teleportation tech that creates a perfect copy somewhere else, but the aliens need to trust that we will ‘balance the equation’ (destroy the original) every time. That’s easy when the human in question is immobilized for transfer. Only one transfer goes wrong- the person being transferred is woken up before the transfer is confirmed, and then the transfer gets confirmed. So now you have the original human, who’s already been copied, and the transfer operator still has to ‘balance the equation’…