But whether the anti-tax, anti-spending alliance behind such antics is a hazard to the political establishment remains an open question.
Hundreds of tax deadline "tea parties" revived the memory of dumping British tea in the Boston harbor before the American Revolution. In Savannah, about 1,500 turned out; many more rallied in Atlanta.
There is talk of similar events on July 4 and of grass-roots pressure on members of Congress. But where do the protesters go from there, and will it matter?
Were they a one-day wonder, or will they become major players on the American political scene?
The consensus: It's too early to say.
Some people, among them Atlanta pollster and consultant David Johnson, compare the tea parties to the tax revolt that began in the late 1970s.
Spawned in California, that movement slashed taxes there and in other states and helped send Ronald Reagan to the White House.
"I think similar frustration is building now," Johnson said.
The target: a system - symbolized by President Obama but not limited to him - that many people think is playing them for chumps.
One sign at a West Virginia rally seemed to say it all: "Taking from the thrifty and giving to the shifty."
Federal megabucks, protesters lament, are raining on executives who ruined their companies and on people who either don't pay taxes or fail to pay their mortgage bills.
And taxpayers who work hard and play by the rules - and their children - are being left to pick up the tab, or so the argument goes.
"By and large, that's what lots of people believe," said state Rep. Ron Stephens, R-Savannah.
But even Johnson, who usually works with Republicans and conservatives, says the current unrest hasn't reached the boiling point.
Moreover, Johnson and others say, the coalition lacks leadership, focus and an event to galvanize it into action.
"They need something that will ignite the spark," Johnson said. "Maybe a really goofy tax plan from Congress or a super-outrageous statement by Obama. They don't have it yet."
Sherry Bebitch Jeffe, a senior policy analyst at the University of Southern California, agreed.
Jeffe noted that the California tax revolt, embodied by the Proposition 13 ballot measure to slash property taxes, had a defining moment.
Shortly before the June 1978 vote, Los Angeles County officials said assessed values - and most likely taxes - were going up more than 20 percent.
"That was the catalyst," Jeffe said.
In any case, Johnson said, the protesters had a rallying cry: "I'm mad as hell, and I'm not going to take it anymore."
The leader of the movement - the late Howard Jarvis - borrowed the mantra from a movie, "Network."
It worked; Proposition 13 passed with 65 percent of the vote.
But so far, experts say, the tea party groups don't have anyone of Jarvis' stature.
"I just don't see anybody like that out there," Jeffe said.
A related problem, many say, is a lack of focus.
Speakers at the tea party rallies lashed out at taxes and spending. But they also bemoaned illegal immigration, gay marriage, gun control and the Federal Reserve System.
"You tend to lose your direction when everyone and his mother gets up and speaks," said Savannah political consultant David Simons. "They need some message discipline."
Stephens agreed, saying a cause should be tightly wound around one theme, or at the most, two or three related ones.
"Otherwise, your message gets diluted and your movement is weaker," he said.
Public not set to party
Apparently there is an even more serious challenge: At least so far, most Americans don't agree with the tea party protesters.
"The public seems willing to go along with Obama's programs as long as they don't seem too permanent," Jeffe said.
Indeed, a recent USA TODAY/Gallup poll supported that conclusion.
University of Georgia political science professor Charles Bullock said the tea parties served mostly to give Republicans something to rally around.
Bullock said they hope news media coverage of such events will amplify GOP critiques of the Obama administration.
"The GOP may also hope that these rallies will energize their base, and that could become useful in the 2010 election cycle," he said.
But Stephens said many Republicans also could have reason to fear the new movement, because they're part of the problem.
After the GOP took over the U.S. House in 1994 by campaigning against Democratic excesses, he said, "all of a sudden, we became them.
"We became even worse big spenders than they were. Maybe this movement gets us back to our roots."