There already exists at least one decentralized prediction market, Augur (based on Ethereum). Unlike centralized ones, anyone can make a contract about literall

There already exists at least one decentralized prediction market, Augur (based on Ethereum). Unlike centralized ones, anyone can make a contract about literally any future hypothetical event and then make a market in it. This can easily be used to create so-called "assassination markets" (a Googleable phrase, not my own). You could simply create a market like "Will so and so die before such and such date?" Then you place a massive bid order at 99.99% odds. Any would-be takers would then have to put up say $1, go out and kill the person before the specified date, and now they're sitting on tokens that are worth $10,000, because the market will resolve to "true."