WASHINGTON -- Lawmakers looking into homeland security officials' practice of monitoring social media sites seized on a report Thursday by a civil liberties group that said taxpayers have shelled out more than $11 million to a private contractor to analyze online comments that "reflect adversely" on the federal government.

In a rare show of bipartisan agreement, members of the House Homeland Security Subcommittee on Counterterrorism and Intelligence held up a report by the Electronic Privacy Information Center (EPIC) as they questioned the chief privacy officer of the Department of Homeland Security. The hearing, titled

"DHS Monitoring of Social Networking and Media: Enhancing Intelligence Gathering and Ensuring Privacy," relied heavily on talking points from a recent EPIC report on nearly 3,000 pages of documents it obtained under a Freedom of Information Act lawsuit. The records detail DHS' online monitoring activities and include instructions to General Dynamics, the private company tasked with trolling the Internet for the agency to analyze comments on DHS or other parts of the federal government.

According to a statement by EPIC, DHS paid more than $11 million to General Dynamics to monitor and prepare surveillance reports on public reaction posted on Facebook and Twitter as well as in comment sections of The Huffington Post, The New York Times, the Los Angeles Times, Drudge, Wired and other media outlets. The intention, it said, was to "capture public reaction to major government proposals" by DHS as well as "positive and negative reports" on FEMA, the CIA and other federal agencies.

Rep. Patrick Meehan (R-Pa.), the subcommittee chairman, and Rep. Jackie Speier (D-Calif.), the ranking Democrat on the panel, both questioned whether DHS was crossing the line between monitoring social media for the public good and trampling First Amendment rights of free speech.

They repeated their concerns in a letter they sent to DHS Thursday. "Although there are clear advantages to monitoring social media to identify possible threats to our security, there are also privacy and civil liberties concerns implicit in this activity," they wrote. "With its domestic mission, the Department of Homeland Security needs to be mindful of the rights of the citizens of our country to express themselves online. Not only should guidance issued by the Department permit analysts to do their jobs identifying threats, but it should also be stringent enough to protect the rights of our citizens."

Sitting in as the ranking Democrat on the House Committee on Homeland Security, Mississippi Rep. Bennie Thompson spoke for other members when he said, "The public must be confident that interacting with DHS on a website, blog or Facebook will not result in surveillance or the compromise of constitutionally protected rights."

Among the documents cited repeatedly by the lawmakers were those obtained by EPIC showing DHS captured public reaction to a controversial proposal to relocate detainees held in Guantanamo Bay, Cuba, to a prison in Michigan.

"This should not be a political operation," Speier said, adding that "capturing public reaction to major government proposals should not be part" of any homeland security monitoring operations.

DHS Chief Privacy Officer Mary Ellen Callahan defended her agency's actions. She said it was limited to outreach to the public, "situational awareness" during natural disasters and other breaking news events, and aiding law enforcement in investigations. She stressed that privacy rules restricted the collection of information on individuals to public officials and "life or death" situations.

"It is the what, not the who, being identified" in Facebook, Twitter and other online posts, Callahan said. She dismissed many items cited by EPIC as being based on outdated information or old ideas that may have been considered at one time but were later rejected and never implemented. "The standard is if you can’t do it offline, you can’t do it online," she said.

But matters were not as cut and dried when Thompson questioned Callahan and Richard Chavez, who heads the DHS operations center that analyzes social media, about whether other federal agencies such as the FBI and Pentagon also keep track of what's on Twitter and other sites. "I can check with my staff," Callaghan said. Chavez added he wasn't aware that other agencies were monitoring websites, a comment Thompson visibly found implausible given recent media reports.

When Meehan, the subcommitee chairman, asked Chavez "who begins the process of identifying what should be analyzed" online, Chavez replied that it wasn't his operations center. After a pregnant pause, Callahan chimed in to say that DHS relies on software that sees whether "train wreck," "derailment" or other key words are trending.

The sparring came a day after Homeland Security Secretary Janet Napolitano testified that "we aren’t sitting there monitoring social media looking for stuff, that’s not what we do," in commenting on two British travelers who were barred from entering the country after one of them jokingly tweeted he was off to "destroy America."