And yet your original post was in response to this:
"If you tell me your name, I'm free to repeat that to whoever I want. If you aren't ok with public information being re-broadcasted, don't go outside."
to which you said:
"Actually in the UK it is covered by the Data Protection Act. Interesting times ahead. If you knowingly or unknowningly give personal information away without my consent this is illegal."
What you're saying now and what you said then are two different contexts.
He wasn't broadcasting his name in the first place; only you had the information (in the limited knowledge of the context). In case you are using this for anything damaging to him or for profit, that is what the Data Protection Act covers. That suddenly his name becomes public knowledge has little to do with this law.
"If you tell me your name, I'm free to repeat that to whoever I want. If you aren't ok with public information being re-broadcasted, don't go outside."
to which you said:
"Actually in the UK it is covered by the Data Protection Act. Interesting times ahead. If you knowingly or unknowningly give personal information away without my consent this is illegal."
What you're saying now and what you said then are two different contexts.