Two bloggers received home visits from Transportation Security Administration agents Tuesday after they published a new TSA directive that revises screening procedures and puts new restrictions on passengers in the wake of a recent bombing attempt by the so-called underwear bomber.

Special agents from the TSA's Office of Inspection interrogated two U.S. bloggers, one of them an established travel columnist, and served them each with a civil subpoena demanding information on the anonymous source that provided the TSA document.

The document, which the two bloggers published within minutes of each other Dec. 27, was sent by TSA to airlines and airports around the world and described temporary new requirements for screening passengers through Dec. 30, including conducting "pat-downs" of legs and torsos. The document, which was not classified, was posted by numerous bloggers. Information from it was also published on some airline websites.

"They're saying it's a security document but it was sent to every airport and airline," says Steven Frischling, one of the bloggers. "It was sent to Islamabad, to Riyadh and to Nigeria. So they're looking for information about a security document sent to 10,000-plus people internationally. You can't have a right to expect privacy after that."

Transportation Security Administration spokeswoman Suzanne Trevino said in a statement that security directives "are not for public disclosure."

"TSA's Office of Inspections is currently investigating how the recent Security Directives were acquired and published by parties who should not have been privy to this information," the statement said.

Frischling, a freelance travel writer and photographer in Connecticut who writes a blog for the KLM Royal Dutch Airlines, said the two agents who visited him arrived around 7 p.m. Tuesday, were armed and threatened him with a criminal search warrant if he didn't provide the name of his source. They also threatened to get him fired from his KLM job and indicated they could get him designated a security risk, which would make it difficult for him to travel and do his job.

"They were indicating there would be significant ramifications if I didn't cooperate," said Frischling, who was home alone with his three children when the agents arrived. "It's not hard to intimidate someone when they're holding a 3-year-old [child] in their hands. My wife works at night. I go to jail, and my kids are here with nobody."

Frischling, who described some of the details of the visit on his personal blog, told Threat Level that the two agents drove to his house in Connecticut from DHS offices in Massachusetts and New Jersey and didn't mention a subpoena until an hour into their visit.

"They came to the door and immediately were asking, 'Who gave you this document?, Why did you publish the document?' and 'I don't think you know how much trouble you're in.' It was very much a hardball tactic," he says.

When they pulled a subpoena from their briefcase and told him he was legally required to provide the information they requested, he said he needed to contact a lawyer. The agents said they'd sit outside his house until he gave them the information they wanted.

Frischling says he received the document anonymously from someone using a Gmail account and determined, after speaking with an attorney, that he might as well cooperate with the agents since he had little information about the source and there was no federal shield law to protect him.

The Gmail address consisted of the name "Mike," followed by random numbers and letters. Frischling had already deleted the e-mail after publishing the document but said he had learned from previous correspondence with the source that he had been hired as a screener for the TSA in 2009.

The agents searched through Frischling's BlackBerry and iPhone and questioned him about a number of phone numbers and messages in the devices. One number listed in his phone under "ICEMOM" was a quick dial to his mother, in case of emergency. The agents misunderstood the acronym and became suspicious that it was code for his anonymous source and asked if his source worked for ICE – the U.S. Immigration and Customs Enforcement.

The agents then said they wanted to take an image of his hard drive. Frischling said they had to go to WalMart to buy a hard drive, but when they returned were unable to get it to work. Frischling said the keyboard on his laptop was no longer working after they tried to copy his files. The agents left around 11 p.m. but came back Wednesday morning and, with Frischling's consent, seized his laptop, which they promised to return after copying the hard drive.

Frischling wrote on his blog that he decided to publish the TSA directive to clear up much of the confusion and speculation that was circulating among the public about changes that were being instituted in airport security procedures after a passenger unsuccessfully tried to ignite a bomb Dec. 25 using a syringe and explosive chemicals hidden in his underwear.

"We are a free society, knowledge is power and informing the masses allows for public conversation and collective understanding," Frischling wrote on his blog. "You can agree or disagree, but you need information to know if you want to agree or disagree. My goal is to inform and help people better understand what is happening, as well as allow them to form their own opinions."

A former federal prosecutor who asked not to be identified told Threat Level that the TSA is being heavy-handed in how it's handling the matter.

"It strikes me that someone at TSA is apoplectic that somehow there's a sense that they're not doing their job right," he told Threat level. "To go into this one reporter's house and copy his computer files and threaten him, it strikes me that they're more aggressive with this reporter than with the guy who got on this flight."

Christopher Elliott, who is based in Florida and writes a column for the Washington Post, MSNBC and others, received a visit from a TSA special agent named Robert Flaherty around 6:30 p.m. Tuesday.

Elliott wouldn't discuss the details of the visit with Threat Level, due to pending legal issues, but he describes in his blog post how he got a knock on his door shortly after finishing dinner and putting his three young children in the bathtub.

Flaherty showed him a badge and said he wanted information about the source of the document he published. When Elliott told him he'd need to see a subpoena, Flaherty pulled one out and handed it to Elliott.

Elliott told Threat Level they talked for 10 to 20 minutes, but he refused to cooperate. Flaherty left but called Wednesday to remind Elliott that he had until the end of the business day to comply with the subpoena.

"I really don't think they thought this one through," said Elliott about the TSA tactics.

Elliott could face a fine and up to a year in jail for failure to comply, according to a statement on the subpoena.

The TSA directive was issued Christmas Day, the date of the attempted attack on Northwest Flight 253, and indicates that the directive will expire Dec. 30. The directive applies to anyone operating a scheduled or charter flight departing from a foreign location and destined for the United States.

It requires all passengers to undergo a "thorough pat-down," which should concentrate on their upper legs and torso, at the boarding gate. It also requires physical inspection of all "accessible property" accompanying passengers at the boarding gate, "with focus on syringes being transported along with powders and/or liquids." It also indicates that restrictions against liquids, aerosols and gels should be strictly adhered to. Heads of state can be exempted from the special screening.

Passengers are also required to remain seated during the last hour of flights, and cannot access carry-on baggage or have blankets, pillows or other personal belongings on their lap during this time.

Aircraft phones, internet service, TV programming and global positioning systems are to be disabled prior to boarding and during all phases of flight. Flight crews are also prohibited from making any announcements to passengers about the flight path or the plane's position over cities or landmarks.

The TSA was embarrassed earlier this month after a contract worker posted an improperly redacted sensitive screening manual on a government site.

That document revealed which passengers are more likely to be targeted for secondary screening, who is exempt from screening, TSA procedures for screening foreign dignitaries and CIA-escorted passengers, and extensive instructions for calibrating Siemens walk-through metal detectors.

Five TSA workers were put on leave pending an internal investigation into how that document got posted.