What scares me is the "hidden" part of it.
There's a difference between privacy and anonymity. There's one thing to have an identity, own it, but protect it (the right to privacy) and then there's a completely different one to hide identity at all and pretend to be anybody, anytime (anonymity).
Anyways, time will tell.
I see no problem with anonymity.
It is on the contrary an advantage of the individual.
And in real life there are property documents, personal expenses and other papers that define the individual.
It smoothes complete anonymity.