The new policies come just a
few weeks after it was learned that Facebook's old data policies enabled an outside research firm eventually hired by Donald Trump, Cambridge Analytica, to collect personal information on some 50 million Facebook
users without their
permission.
Essentially, instead of having a fully public and uncontrolled network and state machine secured by cryptoeconomics (eg proof - of - work, proof - of - stake), it is also possible to create a system where access
permissions are more tightly controlled, with rights to modify or even read the blockchain state restricted to a
few users, while still maintaining many kinds of partial guarantees of authenticity and decentralization that blockchains provide.