As an example, Chainlink is a decentralized oracle network that connects external data to Ethereum smart contracts. Chainlink's decentralized oracles allow smart contracts to communicate with external data, enabling them to execute contracts that make use of information that Ethereum does not have access to. Chainlink's blog discusses how its technology can be used in various ways. Many uses are proposed, including surveillance of pollution or illegal siphoning of water supplies in some cities. Sensors can be used to monitor economic activity, water table levels, and the proximity of bodies of water.

A Chainlink oracle may monitor this data and send it to a smart contract immediately. Based on the data received from the oracle, smart contracts can be configured to impose penalties, provide flood warnings to cities, or penalize companies that consume an excessive amount of a city's water.

Website https://chain.link