The FBI's "Gamergate" file identified at least four men the agency believed were responsible for sending dozens of death and rape threats to women who criticised video games.

They used 4chan and 8chan — websites linked to the distribution of child pornography — to organise their movement, the FBI says.

Two of the men confessed to FBI agents, yet neither was prosecuted.

The victims of Gamergate are frustrated and angry at the lack of action from prosecutors.

Game studio founder Brianna Wu received dozens of threats from Gamergate supporters. Shannon Grant - www.briannawu.net / Wikimedia, CC The day before Halloween, FBI agents showed up at the home of a Massachusetts man linked to dozens of rape, bomb, and death threats targeting women involved in the video game scene. They believed he was a supporter of Gamergate, the militant online movement that wants to end feminist criticism of video games.

The man, whose name was kept confidential by the FBI, confessed: He told the agents that he was a "tech guy," a qualified A++ coder, who played video games a lot and lived with his parents, according to a set of documents the FBI released on its investigation into Gamergate.

He told the agents that he hung out on 4chan, the notorious online image-posting board that — according to the FBI documents — has a history of hosting child pornography. He admitted that he had mocked the women who were targets of Gamergate threats on 4chan, calling one of them "a professional victim who exaggerated the threats."

Then the agents showed him one of those threatening emails. The man said he had created a new email account specifically for the purpose of sending threats to Gamergate targets. He "admitted to sending the threatening email," the FBI wrote in its report, and he "understood the email 'looked really bad.'" Crucially, he also confessed that he knew it was a crime: The man "understood that it was a federal crime to send a threatening communication to anyone and will never do it again," the FBI wrote.

Yet despite all that — an email trail, a confession, and an admission from the suspect that he knew he was breaking the law — the FBI let him go after the suspect said it was a "joke":

The US attorney's office in Boston "declined prosecution of the matter," the FBI report says, adding, "USAO Boston declined prosecution without giving any explanation." The San Francisco office of the FBI, which was leading the investigation, did not have state jurisdiction in Massachusetts and felt it could not pursue charges locally. In conclusion, the unnamed FBI agent on the case wrote, "It is requested that this investigation be administratively closed due to lack of leads."

A representative for the US attorney in Boston declined to comment when reached by Business Insider.

9 months of insanity

For about nine months from the end of 2014 to the summer of 2015, Gamergate targeted women — and a small number of men — whom the movement believed were critics of video games.

The women received dozens of scary late-night phone calls, threatening social-media posts, doxxing attempts, identity thefts, and in one case a successful "swatting" hoax that sent five police officers to a home in Washington state to investigate a false report of a hostage situation. The threats came mostly from male gamers who believe that feminism was damaging video games.

During those months, much of the video game world — which is massive — became obsessed with the idea that women might ruin the future of games by persuading game studios to abandon sexy female characters or tone down the default machismo of male characters. It is difficult to estimate just how big the Gamergate movement really was, but at its height 2 million tweets were sent using the term "Gamergate." About 10,000 users discussed Gamergate on Reddit.

'I will write my manifesto in her spilled blood'

Feminist Frequency blogger Anita Sarkeesian cancelled a lecture because of Gamergate bomb threats. Susanne Nilsson / Wikimedia, CC Gamergate's anonymous rape, death, and bomb threats were intended as a form of punishment for women who published criticism of video games. The perpetrators used fictitious screen names and hid their internet activity behind multiple proxy servers, making it nearly impossible to identify a user, the FBI file says.

To illustrate how bad it was, one of the victims, blogger Anita Sarkeesian, created a Tumblr post showing the dozens of sexually harassing messages she received in response to a tweet complaining about the sheer volume of sexually harassing messages she previously received. (Sarkeesian did not respond to a request for comment from Business Insider.)

Other victims were doxxed, which involves having personally identifiable information published on the internet. Some changed their phone numbers after the numbers were published widely to hostile web forums. One woman, a female executive at Intel who had led a program to support women in the video game business, found that her Social Security number had been stolen and used in an attempt to fraudulently open a bank account, the FBI wrote in its file.

A bomb threat phoned into Utah State University forced Sarkeesian, the blogger, to cancel a lecture she was scheduled to give there. "I have at my disposal a semi-automatic rifle, multiple pistols, and a collection of pipe bombs," a person said in an email sent to university officials before the event. "I will write my manifesto in her spilled blood, and you will all bear witness to what feminist lies and poison have done to the men of America."

A confession on video — yet no charges are brought

The FBI identified a suspect in that case, too, and even obtained a photo of him. But the FBI's Gamergate investigation file — released after a Freedom of Information Act request — indicates that officers never talked to him after one witness was unsure that the photo was clear enough to make a positive identification.

The FBI also identified a suspect — by name, email address, and physical address — whom agents believed was a Gamergate ringleader who organised attacks on 4chan and 8chan. Those image boards were also used as platforms for distributing child pornography, the FBI said in its file. But the file has no indication that the FBI pursued that lead either.

A fourth suspect was recorded on video and audio by the FBI confessing to making 40 to 50 threatening calls, and yet no charges were brought, the file says.

Sarkeesian also received death threats when she went to give a talk in Australia. Photo by Jessica Zollman The release of the FBI's Gamergate file in January provided a treasure trove of information on the real scope of the movement that seemed to overcome the gamer community in late 2014 and early 2015.

Its publication has been welcome by Gamergate supporters, who believe it proves their innocence. The threats were investigated and no charges were brought, they say. The threats, in the eyes of people who hang out on gamer chat forums, were obviously fake; a bomb threat emailed in an attempt to shut down a feminist event at Utah State University said the bomber had "9000" bombs, for instance. Some threats also repeatedly misspelled Gamergate. And after the police investigated, events went ahead and no real violence actually emerged, Gamergate supporters say.

Gamergate supporters also argue that because some of the threats were organised on a website called SomethingAwful.com and not "their" websites, this proves Gamergate was cleared of any wrongdoing.

'All this report does for me is show how little the FBI cared about the investigation'

The victims, unsurprisingly, feel differently.

Brianna Wu, the CEO of the Giant Spacekat game studio, was the target of more than 100 death threats during a nine-month period, she told the FBI and multiple media sources. She received so many hostile messages that she hired people to document them, and at one point she moved out of her house to live in a hotel. She is so angry at the FBI's inactivity that she is running for Congress in the Massachusetts 8th District on a platform of reforming the law to better prevent online harassers.

"All this report does for me is show how little the FBI cared about the investigation. I'm fairly livid," she told Heat Street.

Warning: Some of the language used in these threats is graphic.

Here, Business Insider publishes a digest of the FBI's Gamergate memos, with notations in roughly chronological order. ↓↓↓