How do Ethereum nodes defend against DDoS attacks by mass reading?

Question

Suppose a bad actor has large amounts of data stored on a smart contract. Since reading data is free (doesn't need a transaction), what stops one from simply reading that data over and over again, thus making the node not respond to other read requests?

Answer 1

Nodes and providers maintain their own rate limiting to prevent denial of service attacks. This is no different to any other web application.