Too Long; Didn't Read
Blockchain infrastructures cannot make any veracity guarantees for data that was not natively generated on-chain and not publicly available. The vast majority of the world’s data are not public available. If a person commits fraudulent data into the blockchain, there's no way to ascertain the veracity of this data. The key is to secure the data at the source and capture the data as close to the source as possible. The more intermediaries involved in handling the data, the more you’d have to trust.