(CNN) -- Norway's alleged mass killer testified on Thursday that he played video games as a way to train for a shooting spree that killed 77 people last summer. In particular, Anders Behring Breivik said at his trial that he played "Call of Duty: Modern Warfare 2" as a means of shooting practice, according to CNN's report.
The confessed shooter also said he once played the online game "World of Warcraft," a role-playing adventure with multiple players from around the world, for as many as 16 hours a day.
For people who have long suspected that there is some link between violent video games and real-world violence, the statement offered frightening new evidence for why the video-game industry should be more strictly regulated.
Many gamers and columnists, however, rolled their eyes and collectively muttered "here we go again."
"How many times are we going to do this?" Paul Tassi wrote in a Forbes story, "The idiocy of blaming video games for the Norway massacre." "Really now, it's getting absurd."
"Norway Killer Played World of Warcraft, Which Probably Means Nothing At All," declared a headline on Time.com, which shares a parent company with CNN.
Whether shoot-'em-up video games can incite violence has been a long-running debate among the public as well as in clinical psychology. This type of discussion tends to come up every time it's revealed that a high-profile killer also played video games.
Perhaps the most memorable case study was the Columbine High School shooting in Colorado in 1999, during which experts speculated about the influence of the game "Doom" on the teenagers who carried out that crime.
And for years, the controversial "Grand Theft Auto" series, in which players can kill police officers, was targeted by critics who said it glamorizes criminals and promotes violence. The makers of the game were even sued by the attorney for a convicted cop killer in Alabama, who argued the game inspired his client.
Ultimately, it seems like science should judge whether playing violent video games can lead to a propensity for violence in the real world. A number of recent studies have cast doubts about the link between video games and violence, but there's no definitive answer.
Confusingly, a 2004 U.S. Secret Service and Department of Education report studied 24 cases of school violence and found: "Over half of the attackers demonstrated some interest in violence, through movies, video games, books and other media. However, there was no one common type of interest in violence indicated. Instead, the attackers' interest in violent themes took various forms."
The always-vocal jury of the Internet, meanwhile, rushed on Thursday to the defense of the video game industry. Here's a breakdown of the general argument, in case you want to be supercontrarian and appropriate these points for cocktail-party conversation this weekend.
Point 1: Lots of people play video games and don't kill people.
"How many subscribers do those two games have? Several million? And yet several million of us managed not to go bonkers with a gun," a commenter on my Google+ page. "Ridiculous argument."
Point 1.5: Lots of people who play "FarmVille" don't actually farm.
Here's a related point: People who play other kinds of video games don't usually (or ever) act out the things they do in the games. "Shooters do not create real-life killers. Neither does "FarmVille" create real-life farmers," another Google+ commenter said.
Point 2: The confessed Norway killer had other apparent influences.
"If we're looking for Breivik's influences and motivations, we'd better start with xenophobia, fundamentalist Christianity and right-wing ideology before even mentioning what was in his Xbox," a commenter wrote on CNN's story about the trial.
And from Lisa Smith on Google+: "If there were no violent video games or movies, would Breivek have shrugged off writing his manifesto [on] his irrational fear of Islam? No, then perhaps then if he'd been unable to watch the news? Oops, now we have to keep him from using the Internet, was that enough?"
Point 3: There are lots of ways to train for a shooting spree.
From a Forbes column: "Let's say he did use 'Call of Duty' to help him train in some way. So what? That may sound callous, but let's be real here. If he went to a gun range every single day for the past year, a place that actually trains you how to hit person-shaped targets with a real gun firing real bullets in your hands, would we be talking about how shooting ranges are to blame?
Would we want them all closed down for fear someone else might learn how to shoot a gun and kill someone? Some might, but they'd be shouted down by gun rights activists, ironically many of whom would like to blame games instead."
Point 3.5: And anyway, these games would be crappy for training.
"How can 'World of Warcraft' be considered 'training'? Unless he planned on looting gold and armor. Also, 'Modern Warfare' is hardly a training tool. Too linear and unrealistic," another Google+ commenter wrote. "Could the 'Armed Assault' series, with its more simulation based approach, have been more useful to create a mass murderer?"
Point 4: There's little scientific evidence to suggest video games actually make people violent.
From Time.com: "The most up-to-date research, according to academic and TIME contributor Christopher Ferguson, 'has not found that children who play VVG [violent video games] are more violent than other kids, nor harmed in any other identifiable fashion.'
In Ferguson's own longitudinal studies, recently published in the Journal of Psychiatric Research, he found 'no long-term link between VVG and youth aggression or dating violence.' And Ferguson references another recent longitudinal study involving German children, published in Media Psychology, which similarly found no links between increased aggression and violent video games."
Point 5: The Norway killer apparently saw "WoW" as a cover-up device.
I'll add this little factoid to the pile: If you search the manifesto that's attributed to Breivik, you'll only find a few references to "World of Warcraft." When he does mention the game, he appears to be explaining that by saying if you're playing "WoW" all the time, you can stop family members and friends from questioning what you're up to.
"Announce to your closest friends, co-workers and family that you are pursuing a 'project' that can at least partly justify your 'new pattern of activities' (isolation/travel) while in the planning phase," the manifesto says. "(For) example, tell them that you have started to play 'World of Warcraft' or any other online MMO game and that you wish to focus on this for the next months/year. This 'new project' can justify isolation and people will understand somewhat why you are not answering your phone over long periods."
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