'doxing' is a term that has probably been around for at least 4-5 years. But yea. The point is that you are releasing 'documents' ('dox' being a slur on 'docs') about someone that removes that anonymity.
It's been in mainstream news for about that long, perhaps. The term itself is considerably older.
I did say "at least." :P
Fair enough, but it goes back to at least the 90s from what I can remember. Most likely, it's even older.