David Gerard is a staunch critic of cryptocurrencies and blockchain. He writes the cryptocurrency and blockchain news site Attack of the 50 Foot Blockchain and authored the 2017 book Attack of the 50 Foot Blockchain: Bitcoin, Blockchain, Ethereum & Smart Contracts. David has become an authority on the topic and has briefed the UK House of Commons Science and Technology Committee on the technology. He does not mince words and is clear that he sees absolutely nothing useful about crypto, but sees many negative externalities.