> binding contracts to stock markets, emails, political events) on the other hand how would a contract behave if the required data url is gone (i.e. the weather

> binding contracts to stock markets, emails, political events) on the other hand how would a contract behave if the required data url is gone (i.e. the weather data feed changed from weather.php?v1 to /v1/weather Butekin’s answer to that appears to be that providing the information at the right format should also be an Ethereum contract: users (both participants of your option) would enter another secondary contract with a weather service and pay a small sum is the information is properly available. > wouldn't there be strong incentives for man in the middle attacks to deliver wrong data? Yes, but I’m guessing not more than now… Ethereum offers to automate and lower the cost of such contracts, i.e. replace back-ends. You can imagine testing services remain active on both sides, checking from a distinct source that payments match; that is already what is in place, it’s just a fairly boring activity at the moment.