The origin of 'doxing' on 4chan was to do things like convince a female that was 'attention-whoring' on the forum to do things like post nude photos of herself.

The origin of 'doxing' on 4chan was to do things like convince a female that was 'attention-whoring' on the forum to do things like post nude photos of herself. Some people would immediately try to figure out who she was, in some cases they would do things like send the nude photos to work, school, and/or family, in addition to telling everyone in the forum the name/address/etc of the target. In this sense, it makes sense for the dox'ers to want to remain anonymous. You're convincing someone to do something, then turning it on them to attempt to ruin their life. So 'doxing' is more specifically about destroying someone's anonymity (or pseudo-anonymity if they maintain an alias), at least in it's origins.