Surprised no one mentioned the use of tor for this
http://www.dailykos.com/story/2015/02/11/1363758/-Federal-Judge-Katherine-Forrest-doxed-SSN-posted-on-8ch-net-baphomet-8chan-Admin-Destroys-Evidence8ch.net/baphomet wiped
Biddix's doxing also included bank information and credit scores of the victims. In one case, a man's Paypal was hijacked with nearly 50 grand in it. The SSNs were live for up to two days before the 8chan administrator, Fredrick Brennan, wiped the board in a bid to destroy evidence of this criminal identity theft.
8chan baphomet released the Social Security Numbers of at least fifteen people. The owner of the board, Benjamin Biddix, was one of the most active posters of SSID information. Biddix sold SSNs to other baphomet users via Tor, an anonymous deep-web browser.
Among the victims is Judge Katherine Bolan Forrest, a federal judge serving New York's Southern District court in Manhattan. Forrest's SSN, current address, and eleven of her past addresses were posted on baphomet. She was likely targeted because of her presiding over the Silk Road case, for which a guilty verdict was returned
Forty members of the Boston Police Department were also doxxed. Although their SSIDs were not compromised, their home addresses, phone numbers, and salaries were.
The other victims are private individuals. Many are of retirement age, or approaching it. These people may have never heard of #gamergate or 8chan until anons stole their identities. Biddix freely admitted that those who had their Social Security Numbers posted were "random normies"who had nothing to do with the movement.
Unlike other victims, Judge Forrest's Social Security Number was posted in full, for free, on baphomet. This is likely in retatilation for her presiding over the Silk Road Case. The defendant in that matter, Ross Ulbricht, was found guilty of running the Silk Road online marketplace last week; an online bazaar notorious for trading illegal drugs for bitcoins. It's estimated Ulbricht generated 88 million USD in commissions from this illegal trade. Now convicted, Ulbricht faces life in prison.
The anon who doxed her included a link to Ulbricht's official legal defense fund. But even if there wasn't a smoking gun, 8chan is operating in the same legal gray area as the Silk Road and the Pirate Bay used to do. 8chan hosts illegal content (most famously child pornography) citing the unconvincing argument that their actions are always protected speech under the First Amendment.
Biddix began selling SSNs on 02/05/2015, at one point offering to "dox for hire", including SSNs, for prices ranging from 5-200 USD. Biddix claimed to be doing this because he is homeless and desperate for money. At the time of this writing he is trying to leave the country and settle in China, where he believes he will not face repercussions for his activities.
Fredrick Brennan, the administrator of 8chan publicly told Biddix to knock it off on 02/09/2015, after receiving repeat complaints about the posting of SSNs on the board. Essentially, Brennan admitted that criminal identity theft had been running rampant for two days and threatened to reassign Biddix's board if it did not stop.
Biddix updated his rule set, directing anyone who wanted to continue posting SSNs and bank info (and other illegal content) to do so via Tor.