Facebook cannot be trusted with user data. Moreover, FB will have the ability to access and control user data on the Diem blockchain. Diem is built on a permissioned centralized blockchain. When this experiment began as Libra, the blockchain was permissionless. This switch is telling, and I firmly believe that FB will continue to change the rules as the game plays out. Bait-and-switch is a theme common in FB’s history.
There is a clear distinction between permissioned and permissionless blockchains. Permissionless blockchains are decentralized, pseudo-anonymous (ie mostly anonymous), highly transparent, trustless, and available to the public for participation in consensus validation. These are fully transparent and developed on open-source protocols. Many, including myself, believe permissionless decentralization is the true spirit of blockchain technology. Permissioned centralized blockchains are not anonymous and run-on closed networks where consensus validators are selected. Transparency is controlled by a central authority which also dictates privacy. Diem is permissioned thus privacy depends upon a governing body.
Facebook has neither a body to incarcerate nor a soul to damn. They have a bottom-line and they cannot be trusted. The trustless permissionless decentralized blockchain could remove Facebook’s license to act with impunity, as it often does. A permissioned centralized blockchain operated by Facebook, either overtly or covertly, could grant them an authority that supersede nations.
Trusting Facebook with sensitive personal financial data, is akin to trusting a convicted thief to watch your house while you are out of town. Except it’s not your house, it’s the world economy.