Good one! I didn't consider that the death eaters could do the same thing. But you are absolutely right.

What puzzles me is even now, the only one to use the Time Turner has been Hermione. Dumbledore told her to use it. Why do you think Dumbledore didn't just turn back time himself? Do you think it is because the only ones who can turn back time are the ones who were present when the deed was done? Maybe that's why Harry couldn't go back and save his parents because he would be a baby again. Maybe that's the answer.

Whaddya think?