UGNazi, short for Underground Nazi Hacktivist Group, is a computer hacker group that formed some time in 2011. They best known for their staunch opposition to CISPA and SOPA and practice of Distributed Denial of Service (or DDoS) attacks against United States government websites in retaliation to the bills.
UGNazi attacked the Gamer's League Live website and Ultimate Fighting Championship's website in protest of the UFC's support for the Stop Online Piracy Act (SOPA), proposed by the United States at the time. They later hacked Coach's website for the same reason.
After compromising a database belonging to the Washington Military Department, UGNazi leaked sensitive DNS information used by the US state of Washington. They also leaked the account details of about 16 users, consisting of usernames and password hashes, including those of the website's administrator. "This is just a continuation of our attack against wa.gov, but other than that, like we said we're not done with the government or anyone to be exact. We're going to come after every dirtbag we can get our hands on. Freedom is a right not a privilege but the US government makes it seems like it's a privilege that we have the 'freedom'," a group member told Softpedia.
Softpedia published an article about the attack on the CIA. Hackers of UGNazi are launching attacks on the sites of the CIA and the one of the Department of Justice (DOJ).
In May 2012, UGNazi claimed responsibility for hacking the web server of the web host billing software developer WHMCS in an apparent social engineering attack. A member of the group called WHMCS' hosting provider impersonating a senior employee. They were subsequently granted root access to WHMCS' web server after providing information for identity verification. UGNazi later leaked publicly WHMCS' SQL database, website files, and cPanel configuration. The leaked database contains about 500,000 stored credit card numbers. 
UGNazi member Next claimed that the group targeted WHMCS in response to their tolerance for fraudulent websites' licensed use of their software. Days later, Cosmo released a statement claiming that WHMCS was attacked to demonstrate the vulnerability of their customers' credit card numbers, which were stored on a web server managed by HostGator.
In May 2012, UGNazi targeted the open source forum software, MyBB. UGNazi's Twitter account claims the attack was because the largest hacking forum on the Internet, HackForums, uses the MyBB software. The attack appears to have been done by DNS poisoning. The mybb.com domain had been edited to point toward the UGNazi website. At this time, there has been no evidence of server or data breaches.
In June 2012, UGNazi targeted the well-known imageboard 4chan. They are reported to have hacked CloudFlare's database. The attacks on 4chan were short, lasting about 20 minutes. During that 20 minutes anyone trying to access 4chan would be redirected to UGNazi's Twitter page.
On June 6, 2012, UGNazi attacked the payment processor known as WePay, leaving the website unavailable for 17 hours. People[who?] claim the attack on the WePay website may have resulted in a data breach, but whether it has actually occurred is currently unknown.
On June 8, 2012, UGNazi hacked the website of Wawa, a chain of convenience stores. They defaced the webpage, and have made statements that they have remote access to all of Wawa's gas station terminals. UGNazi has said that the reason for hacking Wawa was to lower gas prices. The Wawa website has since been secured.
On June 17, 2012, UGNazi hacked the website of Six Flags Entertainment Corporation and left the page defaced for over six hours.
On June 21, 2012, UGNazi claimed they took popular social media website Twitter down via a denial of service attack. Twitter was down for two hours, and this was the worst crash the site had faced in eight months. However, "It's doubtful they wrestled down Twitter — it was probably just a bug," said blogger Sam Biddle.
UGNazi hacked into the Twitter accounts of Shirley Phelps-Roper on December 17, 2012, and Fred Phelps Jr. on December 19, 2012, in protest of their Westboro Baptist Church's planned protest following the Sandy Hook Elementary School shootings. Phelps-Roper's account displayed a tribute called 'Pray For Newtown', lending support to those affected by the tragedy. As of the 20th of the same month, Phelps-Roper's account has been returned to her control, whereas Phelps' is listed as having been suspended.
Mir Islam, allegedly UGNazi member JoshTheGod, was arrested on June 26, 2012 in Manhattan as part of Operation Card Shop, a Federal Bureau of Investigation investigation into identity theft and credit card fraud, after allegedly attempting to withdraw money using a stolen ATM card.
Cosmo, another alleged UGNazi member, was also arrested on June 26, 2012 in Long Beach, California as part of Operation Card Shop. The FBI's press release regarding Operation Card Shop states, "In addition, two minors, whose names will not be made public, were arrested by local authorities in Long Beach and Sacramento, California". Two days later, Cosmo was released from a juvenile detention center in Los Angeles and posted on Twitter, which was Cosmo's final tweet for the next two years. 
As of January 10, 2014, UGNazi has announced a return on Twitter which was retweeted by Cosmo.
On November 7, 2012, the 15-year-old UGNazi hacker known as Cosmo or Cosmo the God was sentenced in juvenile court in Long Beach, California. Cosmo pleaded guilty to multiple felonies in exchange for a probation, encompassing all the charges brought against him, which included charges based on credit card fraud, identity theft, bomb threats, and online impersonation, the terms of the plea place him on probation until his 21st birthday. During that time, he cannot use the Internet without prior consent from his parole officer. Nor will he be allowed to use the Internet in an unsupervised manner, or for any purposes other than education-related ones. He is required to hand over all of his account logins and passwords. He must disclose in writing any devices that he has access to that have the capability to connect to a network. He is prohibited from having contact with any members or associates of UGNazi or Anonymous (although Anonymous has no official members), along with a specified list of other individuals. He had to forfeit all the computers and other items seized in the raid on his home. Violating any of these terms will result in a three-year prison term.
Regardless of the loss of Cosmo, the group continued to claim responsibility for hacks in December 2012 of the U.S. State Department and General Services Administration and of Panasonic Brasil. However, they were not heard from until an August 2014 doxing of several prominent people (albeit thinly) related to the #OpFerguson protests concerning the shooting of Michael Brown in Ferguson, Missouri.