Whats Doxing?
Getting all of a person's personal information through online research.
For example, lets start with a username "superhotgirl14"
First thing I do is google the username. If they're signed up on any other websites with that username, they'll pop up, and I might be able to look through their post history and stuff to find info about them like address, state, name, etc etc.
Next, I go to facebook.com/[their username]
So in this case, it would be "facebook.com/superhotgirl14"
If they used the same username on facebook, it will bring me directly to their facebook, giving me huge wealths of information like their real name, state, address, phone number, and other things like that.
After I have their name and state, I can then run a background check on them. Look to see if they have a record, are on the sex offenders list, and other things like that.
So you keep doing stuff like that, trying to find out as much personal information about the person as you can through their username, and I save it all in either an excel file or text file. Normally doxing is used against people trying to harm other people or communities online. Example: If someone signed up here, stayed for a little while, but then started flaming everyone and spreading viruses, I would dox them and post their info here so people could prank call them an annoy them and send them letters and stuff like that.
For more information on what you can do with someone's dox, see Ruin Life Tactics:
Ruin Life Tactics - Insurgency Wiki