This is a bit of a tricky post to write as my first actual real post. It touches on a whole load of topics that are quite controversial. So we'll see how we go - I'm more than happy to enter into a discussion about this topic, as a lot of my thoughts aren't solidly formed yet. Acknowledgements go out to Kelly Hills for discussing this topic with me and helping me solidify some of my thoughts about it.
Background: Reddit and the Reddit Community
Reddit is a website where people post links or write posts (called "self posts"), and then the members of the site discuss them. There are various "subreddits" devoted to different topics - politics, worldnews, formula1, london, dogs, etc. to name a few. Each of these subreddits has a volunteer group of moderators which attempt to keep things on topic and remove spam and obvious troublemakers.
Recently Reddit has come into the spotlight (again!) over some of the less tasteful subreddits that exist in this large mess of a site - r/creepshots, a subreddit devoted to posting stalking-type voyeuristic photos of unsuspecting people, mostly women and girls, and sexualising them. One of the moderators of this subreddit, Violentacrez, was the infamous moderator of a number of subreddits of dubious legality and/or taste such as r/jailbait (for photos of "young-looking" women), which was the subject of a sustained campaign against its existence a few months back due to its acceptance of underage photos (ending up with it being deleted).
r/creepshots and doxxing
After r/creepshots started to get the r/jailbait treatment, including concerned Redditors "outing" the r/creepshots Redditors posting pictures (calling them "Predditors"), Adrian Chen of Gawker decided to dig around in Violentacrez's life and found out who he was, where he worked, and a lot of other personal information about him. This sort of detective work is commonly called "doxxing", and is often used as a weapon by various (usually anonymous or pseudonymous) groups on the internet against someone famous or someone they don't like. In some cases it can turn quite dangerous - on a forum I was once on, a group doxxed a woman who upset some people and her address was posted to Craigslist with an unsavoury message attached to it, resulting in men showing up at her front door.
With Violentacrez outed by Gawker, an outcry went around (some parts of) Reddit, claiming that doxxing him was unethical and calling for the Reddit admins to block all links to Gawker in protest (ostensibly due to a Reddit policy against doxxing). The r/politics moderators blocked the links, and there was a sitewide block for a short time, but this was lifted later as the administrators sorted out their position (eventuating in the block of just the Gawker article that had the personal information on it).
Is doxxing ethical?
In internet research ethics, there's a distinction between public and private data. Anything that is "in the public domain" without requiring passwords or signups is considered public data and usable without general permission required. Data posted in semi-public places but needing passwords (such as closed forums open to signups from the public), is generally considered "private" data, and consent should be obtained before using that in research. Data posted in fully private places (such as locked forums needing moderator approval for access) also requires this consent.
The difficulty comes when you have multiple sources of public or semi-public data that is strung together requiring "detective work" to piece together the puzzle of different internet identities that trace back to the same person, forming a profile of that person that includes personal information. One argument from informed consent theory is that people have a normative expectation of a certain level of privacy that should not be breached - this, in the context of internet research would be along the lines of publicly revealing personal information that has only been shared with a select number of people, for example. Thus, doxxing someone by acquiring personal information and publishing it to a public audience would be seen as unethical, generally speaking.
However, in each case, we need to consider the context of the situation. Violentacrez and the other "Predditors" that post, for example, privacy-invading stalker photos to r/creepshots, are doing so from a position of privilege of anonymity - they are deliberately avoiding any association with their real names for fear of "real life consequences", such as being prosecuted, ostracised from their communities, or having restraining orders taken out on them, for example - all reasonable responses in modern society to such antisocial behaviour.
It is a cowardly act to hide behind anonymity when pursuing harmful activities; these posters claim free speech rights to post such pictures and behave the way they do, but reject it when they are identified publicly (and suffer the consequences of their actions). The importance of transparency and accountability of actions should be weighted far higher than an expectation of privacy in this particular context due to the harm caused when there is no transparency or accountability. Thus, doxxing r/creepshots (and similar) posters is not unethical - it allows victims to pursue further action against them; it allows the posters to be accountable for their actions; and it can act as a deterrent to future actions.