What paradoxes would occur from Television?
With time travel, you could cause things to happen that you know would happen because you went back in time to cause them. Like, let's say when I was little, I was given a book by a stranger, and I used the information in the book to better my life immensely. Later on, I get a time machine, so I take the book back in time and give it to the younger version of me. Where does the book come from?
Not only that, but what about going back in time to say, stop Hitler? It's doomed to fail since Hitler did what he did. If you succeed, then Hitler would have always been stopped by a time traveler, and you would have no need to go back in time to stop him, because someone did it for you, meaning you would not go back in time to stop Hitler, meaning Hitler never got stopped, and so on and so forth.
That's why you shouldn't give something that can travel time to an idiot.
Besides, it's amazingly easy to go fowards in time/accelerate the passage of time, I can think of many ways. Traveling backwards would obviously be much, MUCH harder.