Personally, it would take strong legislation preventing any variation of law enforcement having any access to any of the data, even that of convicted criminals, to make me comfortable to provide mine into the system. Perhaps even constitutional change prohibiting it. Currently, home affairs could feasibly access any data in just about anything the government does with barely a sign-off which I’m not comfortable with.
Our laws protecting us from the government are way too weak for systems like this to take off. Also we keep hiring contractors who do a fairly poor job building the things in the first place.