each member has the right to decide for her/himself whether or not to reveal any of their personal information.
Our curiosity does not create a right to that information.
We do not have a right to any information they don't care to share.
We do not have a right to question their motives, to accuse them of having a personality disorder, or to jump to any conclusions whatsoever about them if they choose to be cautious in cyberspace.
it has occured to me quite often that i have posted far too much Personally Identifying Information (PII) here over the years.
Again ... it's a personal choice and not one to be judged in any way.