Reaction on the Web to the fatal shootings of six people at a Sikh temple Sunday was swift and passionate, dredging up memories of past crimes committed against a religion that has had a presence in the United States since the late 19th century, but remains largely misunderstood.

The Associated Press reported that a 40-year-old Army veteran and white supremacist strode into a Sikh temple in Oak Creek, Wis., with a 9mm handgun and multiple magazines of ammunition and killed six worshippers before police fatally shot him.

Wade Michael Page played in white supremacist heavy metal bands with names such as Definite Hate and End Apathy, according to the Southern Poverty Law Center, after he was demoted and discharged from the military more than a decade ago.

But authorities late Monday had no motive for his actions, which injured three others including a policeman.

Numerous accounts and opinions posted on the Internet said male Sikhs, who wear turbans and beards, are often mistaken for Muslims or members of the Taliban.

CNN reported that Sikhs were targeted by zealots seeking revenge after the 9/11 terrorist attacks. "The first person murdered in retaliation for the 9/11 attacks was a Sikh — a gas station owner in Mesa, Ariz., named Balbir Singh Sodhi who was shot five times by aircraft mechanic Frank Roque.

"In the intervening years, the Sikh Coalition, a New York-based advocacy group, reported more than 700 attacks or bias-related incidents."

The New York Times reported that threats against Sikh-Americans have become acute enough that in April, Congressman Joseph Crowley, D-New York and co-chairman of the Congressional Caucus on Indians and Indian-Americans, has requested the FBI collect data on hate crimes committed against them. In the previous year alone, he said in a letter to U.S. Attorney General Eric Holder, two Sikh men in Sacramento were slain, a Sikh temple in Michigan was vandalized, and a Sikh man was beaten in New York.

Valarie Kaur, a filmmaker who has chronicled Sikh attacks for 11 years, said in a statement that the shooting "is reverberating through every Sikh-American home," where the worst is feared.

"We are experiencing it as a hate crime," she said. "Every Sikh American today is hurting, grieving and afraid."

Simron Jeet Singh, a doctoral student at Columbia University, warned in HuffPost that fear and negativity are foreign to Sikh vocabulary and that "becoming cynical and negative might lead us down a slippery slope.

"So, I am making a conscious decision. I am refusing to accept that human beings are malicious and hateful, and I am rejecting the notion that we need to live in fear," said Singh.

HuffPost's senior religion editor, Paul Brandeis Raushenbush, wrote that the need for Sikhs to explain they are peaceful or for the media to point out that Sikhs are often mistaken for Muslims is disturbing.

"This is a good learning moment for the American people of all religions, and especially for the American media," he said. "Yes, Sikhs are not Muslims and Sikhs are not Hindus, but jumping to clarify (the) difference leaves the unfortunate, if unintentional, perception that there is something wrong with those 'others.'"

He said that Sikhs had told him that an upside to Sunday's tragedy "would be for Americans to become more familiar with the Sikh faith and to understand that they are a beautiful part of the fabric of American spiritual practice."

In that effort to educate people about Sikhism, HuffPost published a story on "5 things to know about Sikhism." Among the five points was some brief background explaining that Sikhism was founded in the Punjab region in India in the 15th century by Guru Nanak Dev. Sikhism broke from Hinduism due, in part, to its rejection of the caste system.

Sikhs were among the first immigrants from South Asia to enter the United States, wrote Deepak Sarma, a professor of south Asian religions and philosophy at Case Western Reserve University. "Sikhs began working on the railroads in Oregon and as farmers in California at the end of the 19th century. Having lived in the United States for more that 130 years they ought to be among the ordinary, the common, the least different. So why are 'we' not used to them by now?"

He concluded, "I do know that I will be 'different' unless or until Americans become more educated and more accepting."