So howls someone on the Reddit forums. Apparently it means that someone has garnered all your private information by fair means or foul and put it up on the net for all to see, thus I’ve been doxxed! The origin in documents is pretty clear but has this term been around long or is it a relative newcomer (say the last year or so)?

Dox meaning documentation isn’t new, I’ve been seeing it from 1337speakers for a decade or so and it might well be much older than that, for all I know.

Dox as a verb is, I think, newer.

Urbandictionary has a relevant entry from early 2010.

This blog from Feb 2010 uses the term:
https://whatladder.wordpress.com/tag/hella-doxed/.

Google Buzz seems to have merrily doxed everyone and assumed that you want everyone you email to know who else you email.

My quick Googlation attempts don’t turn up anything earlier than 2010.

Note that as well as doxed and doxxed, you’ll do well to include the various 1337 variants in your searches: d0xx3d, d0><3d etc.
http://www.scatchan.net/topic/16009

How do you feel, knowing that you will never know who d0xx3d you?

A search of Usenet posts turns up some earlier uses of doxed or doxxed.

One use is figurative for “screwed, anally raped.” Urban Dictionary has this one too. The Usenet posts using this date to 2001. No clue what the origin is. It appears to be especially popular in the online gaming world, and might—I’m just guessing here—have something to do with casting spells in a fantasy game, as that’s the context a lot of the citations appear in.

Another is in reference to VHS tapes or DVDs, you get “doxed sets,” which I at first mistook to be a misspelling of “boxed,” except the phrase “boxed and doxed sets” is rather frequent.

I would suggest the first meaning above blended with the “documents” sense to give the specific meaning of private information being revealed.