[heavenlyblue]

If it's authed all the way down to your SSN, it means that government owns the identities used in the system.

What exactly do you need a blockchain for in such a scenario? Ah right - the unchangeability.

Well, then it means that in all scenarios with the stolen identities we would need to provide for a mechanism to delete the reviews, based on the government-provided data on distrusted SSNs.

In a scenario where we don't allow the reviews to be post-deleted, we are rampantly increasing the value of stealing an identity, which means that the motivation for that goes up a lot.

Now, it means that the only entity that is actually responsible for the correctness of the data in our database is the government.

Now, why do you need a blockchain for that if you could simply have a database backed by the government in the first place?