Disagree with slide three on "private blockchains". Weaver underestimates the difficulty of reaching consensus among a fixed set of participants by assuming the

Disagree with slide three on "private blockchains". Weaver underestimates the difficulty of reaching consensus among a fixed set of participants by assuming there is just one party that signs blocks. If there is more than one party you end up in the land of BFT. Distributed systems are hard to build. Additionally a solution which is trivial to implement makes that solution good. I wish we had more trivial solutions to these problems.