WASHINGTON — The U.S. government has quietly recast policies that affect the way information is gathered from U.S. citizens and others crossing the border and what is done with it, including relaxing a two-decade-old policy that placed a high bar on federal agents copying travelers' personal material, according to newly released documents.

The policy changes, civil liberties advocates say, also raise concerns about the guidelines under which border officers may share data copied from laptop computers and cell phones with other agencies and the types of questions they are allowed to ask American citizens.

In July, the Department of Homeland Security disclosed policies that showed that federal agents may copy books, documents and the data on laptops and other electronic devices without suspecting a traveler of wrongdoing. But what DHS did not disclose was that since 1986 and until last year, the government generally required a higher standard: Federal agents needed probable cause that a law was being broken before they could copy material a traveler was bringing into the country.

The changes are part of a broader trend across the government to harness technology in the fight against terrorism. But they are taking place largely without public input or review, critics said, raising concerns that federal border agents are acting without proper guidelines or oversight and that policies are being adopted that do not adequately protect travelers' civil liberties when they are being questioned or their belongings searched.

"For 20 years, the government has at least implicitly recognized there were some First Amendment restrictions on reading and copying documents," said Shirin Sinnar, a staff attorney with the Asian Law Caucus, which along with the Electronic Frontier Foundation sued the government under the Freedom of Information Act for disclosure of border search policies. "It's disturbing now that the government has jettisoned that policy in favor of one that violates First Amendment rights."

DHS spokeswoman Amy Kudwa said the updating of policies reflects an effort to be more transparent. In an e-mail, she wrote the decision of U.S. Customs and Border Protection "to change some of the standards in its old policies reflects the realities of the post-9/11 environment, the agency's expanded mission and legal authorities, and developments in the law, including the Homeland Security Act of 2003. Although certain aspects of the policies have changed, the policies have always reflected the notion that officers have the constitutional authority to inspect information presented at the border" without requiring suspicion of a particular traveler.

The 1986 policy was issued after a lawsuit was filed by a group of activists returning from Nicaragua who had their diaries, datebooks and other personal papers seized and photocopied by customs officers and shared with the FBI. The government argued the customs agency had the right to enforce a law against importing subversive literature.

"Essentially they were using that as a pretext to do intelligence gathering on critics of our policies on Nicaragua," said David D. Cole, a Georgetown University law professor who was then a lawyer at the Center for Constitutional Rights, representing the activists suing the government in Heidy v. U.S. Customs Service.

To set guidelines on document searches, the agency issued the 1986 directive that made clear that its officers "as a general rule ... should not read personal correspondence." But, the policy noted, officers had the authority to scan material for evidence of violation of laws pertaining to copyright, sedition and contraband. With reasonable suspicion of a violation, they could detain the material. With probable cause of a violation, they could seize and copy it.

In July 2007, the government dropped the requirement that there be reasonable suspicion to review material but specified the review had to take place in connection with laws enforced by CBP, according to a copy of a policy the groups obtained.

Then, this July, the government issued its broadest policy to date regarding information searches at the border, allowing documents and electronic devices to be detained for an unspecified period. Moreover, they may now be copied without any suspicion of wrongdoing, the lowest legal standard.

"The tragic events of 9/11 required the federal government to re-examine its law enforcement and counterterrorism efforts to ensure that all legally available means are employed to prevent another attack," Kudwa said.

But Marcia Hofmann, staff attorney for the Electronic Frontier Foundation, said laptop computers may contain "a massive amount of private information such as personal e-mails, financial data or confidential business records," and the government should not violate travelers' constitutional rights in the name of national security.

Customs officers are trained to know under what circumstances sensitive law enforcement information may be shared and with whom, DHS spokesman Russ Knocke said.

Over the past several years, the Asian Law Caucus and other civil liberties groups have reported a surge in complaints from travelers who have been questioned about their religious practices and political leanings. Many of the travelers say they have had their laptops or phones searched.

Yasir Qadhi, a 33-year-old Houston native who studied in Saudi Arabia from 1995 to 2005 and is pursuing a doctorate in Islamic studies at Yale University, said he is questioned every time he re-enters the United States. He said he is routinely asked which mosques he has prayed in, what charities he donates to, what lectures he has delivered, what the lectures are titled. If he has notes, he said, they are photocopied.

Knocke said he could not comment on an individual case. He said customs officers do not racially profile in any way but have the authority to "take and consider evidence concerning the privilege" of any person to enter the United States.

Nathan A. Sales, former DHS deputy assistant secretary for policy development, said "in some instances, you can imagine it would be appropriate to ask questions" such as those asked of Qadhi. "But when you do, you're playing with fire."

Qadhi said he feels "frustrated" by a system he thinks will never tell him what list he is on so he can get off it. "I'm treated like a second-class citizen, and there's absolutely nothing I can do," he said. "This is simply not the America I grew up in."