Assuming time travel is possible. I do not see how one could band it from being used. In fact, how would one even know that it was used? If you buy into the multiple universe intrepretation of quantum mechanics, would not the time traveller simply pop out of existence in our universe never to be seen again? How would it be possible to band time travel in the infinite multitude of parallel universes, since each universe represents one of an infinite albeit different sequence of events/choices? To “fight” against the infinite diversity of existence in all of its infinite combinitations does not seem logical (at least to me that is). And if you do not buy the multiverse idea, then if time travel is to be used it can not be stopped since time travel would only be possible on closed time like curves, i.e. self-fulfilling destinies in a manner of speaking. Personally, I do not even see how it is possible for one to realize that they were in a closed timelike loop much less escape it. For all things would be as they were as they are and as they will be. Actually, a lack of multiple universes seems a little depressing to me. It seems it would imply an unchangeable fate, for whatever actions we take we were destined to and no matter what technologies we may think up would be able to erase the mistakes of our past or change the past course of our existence. And if that is in fact the case, the only real benefit time travel would have is for scientific and historical purposes. Unless, you were killed by a time traveller from the future but if that happens you need not worry because it was suppose to happen!