Binary options are illegal in many countries for two very good reasons. First, the vast majority of binary brokers are nothing but deposit-only scams. Second, binary options is a simple up/down bet. It's like betting red or black at roulette, except that the payouts are much worse than any licensed casino.At a casino's roulette table, you are not betting against other players. You are betting against the house. At a binary broker, there is no outside liquidity provider. Your wins come out of the broker's pocket and your losses go into the broker's pocket. This give those few binary brokers that aren't deposit-only a strong motivation to find ways to claim that successful trades were somehow cheating.
If you want to gamble, go to a licensed casino. The payouts are better and if you win, you know you can cash out your chips without any problems. If you want to trade or invest, avoid binary options.