Too Long; Didn't Read
There are hundreds of blockchain projects proposing to “disrupt” real-world industries, from insurance to sports betting. There is no feasible way for a smart contract to look up external data on its own. The provider of external data can choose to falsify it, or someone can interfere to tamper it. All betting and gambling projects have to make sure that the event results they feed into the contract are reliable. There are no universally respected oracles in this field, like Bloomberg for stock exchanges.