[WalterSear]

Slightly ridiculous. Blockchains enforce the contract on the blockchain.

The contracts don't, and can't, concern themselves with anything that is off the blockchain. Once the ether is in your account, the contract is complete.

[lenticular]

They enforce the contract on the blockchain, but that's pretty much irrelevant, since breaking a contract usually doesn't involve anything a blockchain solution would control.

As an example, fradulent fish is a huge problem in the fisheries and food industry. At every step of the supply chain, there is temptation to substitute expensive for cheap fish. Most Chilean sea bass you buy isn't actually Chilean sea bass, for example.

A lot of people are hyping blockchain as a solution to this serious problem, not appreciating the fact that the technology cannot actually tell different types of whitefish apart. I really would like a solid counterexample where blockchain actually would help, but I've never heard one.