I think you're making this unnecessarily complicated. Names are personal but not private and
the accepted means of referring to a person, so if you feel like telling all your friends, go
right ahead. You just don't have a reason to tell them his tax file number, bank account
details or credit card number. There may be restrictions on publishing his name in the
newspaper also.
I think you're referring to the idea that personal data should never be shared (which I never
said), which is obviously absurd... It's just not a free-for-all either. Like most of the real
world it's a nice shade of grey.