'There are thousands of angry White men like Page out there'

While private groups had been quietly monitoring the Wisconsin Gurdwara shooter and his racist leanings for years, Wade Michael Page was not on the radar of the Federal Bureau of Investigation.

This became clear as at least two private groups, which monitors the activities of extremist and hate groups, said Page was on their monitoring list and came out with details on the alleged shooter, while the FBI -- the national agencies entrusted with such a task -- saying that the lone gunman was not on its radar.

"Law enforcement is challenged every day to balance the civil liberties of US citizens against the need to investigate activities of possible criminal conduct.

"No matter how offensive to some, we are keenly aware that expressing views by itself is not a crime," FBI spokesman Paul Bresson said.

However, Anti-Defamation League and South Poverty Law Centre was on their tracking radar for quite some time.

"When we know that an extremist is talking about taking violent action, we will definitely share that information with the Justice Department but there was no reason to believe he was going to take this kind of action," Marilyn Mayo, co-director of the Anti-Defamation League's Centre on Extremism, was quoted as saying by the Sacramento Bee.

Meanwhile, South Poverty Law Centre (SPLC) said "right-wing extremism" proponents have commended the actions of Page.

"You don't belong here in the country my ancestors fought to found, and deeded to me and mine, their posterity," wrote Alex Linder, the foul-mouthed neo-Nazi who operates the racist website Vanguard News Network (VNN), on his forum, SPLC reported.

SPLC, which monitors such websites and hate groups, said that others on VNN made similar remarks stating that Page was not alone.

"There are thousands of other angry White men like Page out there, the vast majority of them unknown," a commenter named OTPTT wrote.

"When will they, like Page, reach their breaking point, where they give up all hope for peaceful activism, and reach for their guns and start shooting at the first non-Whites they see?" the commenter wrote.

Larry Loper, head of the Pennsylvania chapter of the Hammerskins, a violent skinhead group, paid tribute to his fallen "brother" on Facebook.

"I really don't feel to disagree or agree what Wade did," Loper wrote.

"All I feel is loss and sympathy for a brother that was overwhelmed by pain and frustration. I could care less though for those injured and wounded other than Wade," he wrote according to SLPC.