Morph: Its not private. Its not confidential. Its nothing.
Yes, pretty much all that information is far from private. It is really, really difficult to stay under the radar in today's world. If someone wants that information, most of it is accessible somewhere.*
I am thinking that the paranoia that people are feeling over this isn't so much those issues - what could be the concern is that this information identifies them as Jehovah's Witnesses. They don't want other people/institutions or the government knowing that they are JWs.
Being officially identified as a Jehovah's Witness makes them feel vulnerable. They have pictures of bunkers in their brains.
It isn't just that they don't trust the WT/org. They distrust everybody else.
*edit to add - what I have found is that is has become increasing difficult to connect actual people with their JW affiliation. It used to be easy. There are individuals who are fairly prominent in certain industries/careers who have learned to guard their JW identity