The 51% scenario: just install more hash power. That would be cheaper and would not risk anyone's life. Protecting cryptocurrency: there are cryptographic ways

The 51% scenario: just install more hash power. That would be cheaper and would not risk anyone's life. Protecting cryptocurrency: there are cryptographic ways to achieve very high security that are free or very inexpensive. Physical encryption keys cost under $100. Combine those with multiple signatures and offline storage in a safe deposit box and you have several physical and cryptographic layers of security for pretty cheap. Services that do those things do not need to be very expensive. Too many scams? Point taken. We will still need police. BTW there's a reason I said cryptocurrency and not Bitcoin. Bitcoin is one of the slower cryptocurrencies. Energy spent securing the chain is per block, and its block size limit and other aspects of its design artificially boost its energy per TX. That and in the long term I expect people to find less energy intensive ways to secure block chains.