The Web was studded with praise for Stack almost immediately after his plane slammed into the Austin office complex Thursday morning. The admiring salutes appearing on sites ranging from Facebook to the pages of extremist groups reflect what experts say is an "explosive growth" in the anti-government patriot movement.
"Extremist groups are already aligning behind [Joe Stack], beginning to talk about him as a hero," said Mark Potok, director of the Southern Poverty Law Center which studies American militia and hate groups. "The growth of those groups has been astounding."
Stack's suicide note, an angry rant against the IRS and the government which was posted online the morning of his death, got around 20 million hits before it was taken down at the request of the FBI, according to Alex Melen, president and founder of T35, the network service provider for the Web site where the note was posted.
Melen, 25, said within minutes of taking the note down, the company was "bombarded" with around 3,000 e-mails demanding Stack's words be reposted. Some of the e-mails contained personal threats against Melen.
"What's funny is most people were pretty much praising him," Melen told ABC News.
Bob Schulz, founder of the anti-government We the People Foundation, said that while he only advocates non-violent means of protest, he can understand Stack's motives and said it is a reflection of a movement unlike any he's ever seen.
"There's a huge patriot movement," Schulz said. "I've been doing this kind of work for 30 years. Never have I seen the likes of what's going on now. It's delightful."
The anti-government movement gathered strength during the early 1990s, resulting in several high profile stand-offs with the FBI. Anti-government militias trained in the woods and prepared for a confrontation with the U.S. The militia movement peaked in 1995 when Timothy McVeigh and Terry Nichols bombed the Murrah Federal Building in Oklahoma City, killing 168 people.
The anti-government movement became dormant until the mid-2000s. Potok said a militia and extreme anti-government movement, fueled initially by anti-immigration sentiment, is back in a big way, especially since President Obama took office.
According to an April 2009 report by the Department of Homeland Security, the current anti-government climate "parallels" what federal officials saw in the 1990s.
"Rightwing extremists have capitalized on the election of the first African American president, and are focusing their efforts to recruit new members, mobilize existing supporters, and broaden their scope and appeal through propoganda, but they have not yet turned to attack planning," the report said.
For many, Obama's election was a near perfect storm of disappointments, Potok said.
"The longer term thing goes back seven or eight years due to immigration," Potok said citing the surge of border patrol militias like the Minutemen. "But Obama's election, which is in a way related to the non-white immigration issue, was representative proof that this country is irreversibly changing demographically. Then the economy has played a role and things have gotten worse and worse."
The result is what Potok referred to as a "broad-based, right-wing populist rebellion," generally short of violent extremism.
Expert: Violent Acts 'Inspire' Extreme Groups
While not necessarily extreme itself, many groups in the overall movement are "shot through with radical ideas, conspiracy theories and racism," Potok said. "Sometimes these attacks do serve as inspiration for other groups and individuals."
One reason anti-government groups are embracing Stack, rather than distancing themselves from his extreme actions, is that he does not seem to be crazy, Potok said. It's a characteristic that troubles forensic pyschiatrist and ABC News consultant Dr. Michael Welner.
"It's easy to get a sense that someone like snaps," Welner told "Good Morning America" today. "But this is the kind of crime that's planned for a long time... I don't find it to be psychotic. That's the problem here. It's rational."
Schulz believes Stack was simply beaten to the point of desperation by the government.
"The government is routinely allegedly violating the Constitution... Then when you call them on it, they ignore you too. That's enough to drive a lot of people together and to start, you know, some kind of movement," he said. "There are people that are out there so frustrated that say 'Hey it's time to lock and load.'"
Online Posting: 'Prepare for Battle!'
Schulz compared Stack's attack to McVeigh's Oklahoma City bombing, saying despite the desperation, any violent act is detrimental to the movement.
"Anybody that commits a violent act against the government sets things back," Schulz said. "The government uses that as more reason to further clamp down... Timothy McVeigh set things back. Joe Stamp set things back."
Online, it appears that many people disagree.
"He sacrificed his life to inspire the quest for TRUTH," one Facebook poster said. "He deserves a memorial. A one man uprising... God Bless him."
"This was quite heroic," said a member of Stormfront.org, a white supremacist Web site. "There is a gradual awakening underway."
"This is just the beginning, prepare for battle!" another said.