Let’s say you can travel at 10c. At Point A, the Arlington Photons win the Galaxy Cup 1-0. You zip to Point B and place a bet on that game, borrowing the money

Let’s say you can travel at 10c. At Point A, the Arlington Photons win the Galaxy Cup 1-0. You zip to Point B and place a bet on that game, borrowing the money to place that bet from the Baltimore branch of the Arlington Legbreaker Gang. Wait for the photons, collect your winnings at Point B, then zip back to Point A ahead of your loan. The loan info arrives at Point A, and you pay it off a microsecond later, and pocket the difference. Congrats, you have just traveled “back and forth” through time. To people in both the Point A and Point B reference frames, you have “seen the future” and acted on it. Now, the Legbreakers aren’t stupid. Once they know someone is screwing around with FTL they’ll just hold bets and payoffs until light can travel. Yes, but… how do they synchronize their clocks between A and B? And how can they distinguish between a lucky person and a time traveler? Etc etc, ad regressum. "Now" and "Here" as fundamental concepts only make sense inside a single reference frame. If you break the idea that information has a speed limit, then both of those ideas shatter into tiny little pieces.