Last December, I met with senior Swedish officials, including a cabinet minister, over security concerns related to the safety of the Jewish community. Truth be told, I didn’t make much progress. It was explained to me that authorities have a list of about 800 extremists, roughly divided between Islamist militants and far-right neo-Nazis. Subtext: We have the situation in our country under control. “Was Taimur Abdulwahab al-Abdaly on your list,” I asked.

The answer was no.

Authorities were apparently clueless about the radicalized Iraqi-born Swedish citizen who blew himself up prematurely in the heart of Stockholm, just yards away from hundreds of Christmas shoppers.

Sweden dodged a bullet that day, but Norway had no such luck.

In the wake of the carnage carried out by Andres Behring Breivik, authorities expressed shock he had escaped their scrutiny, since they had long-since infiltrated extremist groups.

Welcome to the era of the leaderless, "Lone Wolf."

"Lone Wolf," or leaderless resistance, probably traces back to anarchists of the late 19th century but re-emerged a quarter of a century ago in the United States when, in reaction to the government's successful infiltration of violent groups like The Order,  ex-klansman Louis Beam urged like-minded, anti-government extremists to re-form into small, untraceable cells.

That strategy has been deployed across America’s political and social spectrum: from radical environmentalists and animal rights protesters, to extreme anti-abortion activists, to Oklahoma City bomber Tim McVeigh, and neo-Nazi types.

In 1999, one of them, white supremacist Buford O. Furrow, Jr., went on a lone wolf terror rampage in Los Angeles, shooting up a day camp at a Jewish community center and murdering a Filipino-American postal worker.

The ultimate “lone wolf,” of course, was Unabomber Ted Kaczynski. Indeed, Andres Beivik ripped off parts of the Unabomber’s writings in his 1,500-page cut-and-paste manifesto.

But there are profound differences between the ultimate loner, Kaczynski, and Breivik. The self-appointed latter day Templar was quite social and gained empowerment and validation from like-minded bigots while evading police scrutiny. How?

The Internet.

Intelligence and police agencies in the UK and the U.S. already have their hands full with Al Qaeda's decentralized Internet-based recruitment of individuals or small groups, who act without central direction. Deadly examples include the 7/7 London bombers and Colonel Hassan, the perpetrator of the Fort Hood Massacre.

And now the attacks in Norway.

There is, for now, no neo-Nazi guru of terror equivalent to Sheik al-Awlaki, but there is a significant subculture of hate pre-positioned to validate and inspire bigots like Breivik.

Take, for example, the Swedish Nazi web forum Nordisk (Nordic) that Breivik has been an active member of since 2009. Some members have called for political terrorism and bomb attacks on government buildings.

According to the anti-Nazi group EXPO, the common denominator of the Nordisk Forum online community is a hatred for immigrants and a multicultural Europe.  Discussions went way beyond pseudo-intellectual posturing. “The Turner Diaries,” the book labeled “the terrorist bible” that inspired the Oklahoma City bombing (using a fertilizer-based bomb) was also promoted in the Forum.

And in March 2010, EXPO reported the anonymous posting:

"Cars parked by a large building carrying fertilizer and gasoline can make a nice explosion. The skyscrapers will come down like the twin towers of the World Trade Center. We are not talking about killing people. We hope the buildings will be empty, but if they aren't, that will be unfortunate ... I don't understand why people are not aware that we must wage war. Leading politicians in the government, who live at a remove from the threat that immigrants pose, have decided they can come here to live with us in our society. They are misusing what our ancestors built here. In my opinion, nothing you could do to those creatures would be immoral."

Breivik appears to have used the full spectrum of the Internet. The Norwegian newspaper Verdens Gang reports that Breivik has posted at least 75 Islamophobic and racist commentaries on Facebook.

"When will multiculturalism stop being an ideology designed to disintegrate European culture, identity, nation states and traditions?" Breivik demanded.

Authorities are combing through Breivik’s property and belongings to try to ascertain how he learned to build so powerful a bomb. In fact, you don’t have to go far beyond YOUTUBE, which boasts dozens of how-to videos instructing the uninitiated about converting a cellphone into a detonator and other practical tips to blow up a watermelon or your neighbor.

So while bowing our heads in prayer for the innocents and innocence lost in Norway, we all need to come to grips with the growing threat of digitally inspired lone wolves. Hate may be as old as Cain and Abel, but the combination of hate and technology presents a new threat we have yet to fully fathom, let alone thwart.

Rabbi Abraham Cooper is associate dean of the Simon Wiesenthal Center and directs the Center's Digital Terrorism and Hate Project.