Other witnesses at Tuesday's hearing represented groups that varied in size and mission, including local tea party chapters. All offered similar testimony about an application process for tax-exempt status that they saw as overly intrusive and treatment from the agency that one argued was criminal.

"I honestly have lost sleep in fear of what our government might do next," said Dianne Belsom, president of the Laurens County Tea Party in South Carolina.

Kevin Kookogey, founder of a group called Linchpins of Liberty, said delays in obtaining nonprofit status cost his group a $30,000 grant. He asked why the IRS needed him to identify his mentoring group's members — many of them minors.

Becky Gerritson, president of a local tea party group in Alabama, choked up while describing a nearly two-year quest for nonprofit status. She told lawmakers she feared that the America she grew up in was "slipping away."

Separately, the Republican-led House Oversight and Government Reform Committee released the findings of an audit by the Treasury Department's inspector general examining the agency's expenditures for employee conferences over a three-year period.

The audit focused on a single meeting in Anaheim, Calif., that cost $4.1 million — a figure the inspector general argued could have been negotiated down.

"The wasteful Anaheim conference is one example of a culture of excess that plagues the IRS and many federal agencies," said Republican Rep. Darrell Issa of California, the committee chairman. "Taxpayer money meant to pay for a core agency mission, the hiring of more enforcement personnel, was instead spent on a lavish party."

Tribune Newspapers' Washington bureau contributed to this article.