So, in the Star Trek universe, if we are right-thinking people, it looks like we can't really decide whether murder is wrong or not.
If Kirk wants to save the world while not breaking a lunch appointment, he can just send a copy of himself off to die heroically, and go for lunch. The copy can feel free to die heroically in a good cause, and if he doesn't, he can teleport home safe in the knowledge that he will never get there.
Oh come off it! At some point we have to draw the sodding line and say that randomly creating copies of people and then painlessly killing them is wrong, don't we?
But notice that there is no difference at all in the predictions of our various theories of consciousness and personal identity.
The only one that made a difference to what we anticipate seeing is Cartesian Dualism / Souls. The first time you operate a transporter you get a guy going "Grr.. Aaargh.. Brainszzz.. ", remember?
So we ruled that one in or out early doors.
All the other theories are about what it feels like to be transported. But we can't find out without actually being transported.
All the other theories make exactly the same predictions about what other people will say about the experience. They will say things like "Relax, don't worry. You step into the transporter, and then you step out on Mars. Doesn't hurt a bit. Feels like your soul comes along with you."
They don't even make any predictions about what you remember. You remember being transported hundreds of times. It's always fine. Works just like it says on the adverts.
And if the right-thinking people are right, that's just what's happening.
And if they're not, when you step into the transporter you die.
Won't actually make any difference, mind. You'll get out the other end and say: "No, feels fine.", "Looks like materialism is the way to think about all this.".
And you'll still be thinking along these lines when you get home and find the real you fucking your wife.