> If I (a trusted third party) maintained a giant public database that anybody could append to You're opening yourself up to equivalent of DDoS for databases.

> If I (a trusted third party) maintained a giant public database that anybody could append to You're opening yourself up to equivalent of DDoS for databases. Add extra maintainers for redundancy and economically incentivise people to act in good faith. Congratulations, you now have a proof of stake blockchain.