WASHINGTON (CNN) -- Amir Khan says he becomes frustrated and humiliated every time he enters the United States and federal agents search his computers. Khan, a Pakistani-born U.S. citizen, says it has happened five times since 2003.

A suit filed last week seeks clarification on the rules that allow federal agents to search laptops and other devices.

He says agents with U.S. Customs and Border Protection have even forced him to give them access to password-protected, confidential information from his company and his banking records.

An IT consultant who travels to Europe, Turkey and Pakistan, Khan says he has cooperated with the questions and searches but feels by now border agents should know he doesn't pose a threat.

Situations for travelers such as Khan are at issue in a lawsuit filed last week by the Electronic Frontier Foundation and Asian Law Caucus in U.S. District Court for the Northern District of California.

The suit accuses customs agents of "lengthy questioning and intrusive searches" and seeks clarification on the law that allows such searches.

The San Francisco, California-based foundation, which works to defend people's rights in the digital world, says it knows of more than a dozen cases in which electronic devices such as cell phones, BlackBerries, MP3 players and laptops have been searched by customs agents. In some cases, they have been confiscated and never returned. Watch cyber searches at airports »

"Plaintiffs seek agency records in order to determine what policies and procedures exist governing CBP's questioning and searches of individuals at the nation's ports of entry," the suit says.

The Customs and Border Protection defends the searches, saying the agency does not need to show probable cause to look inside suitcases or laptops.

"We have broad search authority at the borders to determine admissibility and look for anything that may be in violation of criminal law," says agency spokeswoman Lynn Hollinger.

Hollinger says electronic devices could contain evidence of possible ties to terrorism, narcotics smuggling, child pornography and other criminal activities.

Russ Knocke, a spokesman for the Department of Homeland Security, equates searches of electronic devices to those of papers in briefcases.

"You forgo your right to privacy when you are seeking admission into the country," he says. "This is the kind of scrutiny the American public expects."

But Marcia Hoffman, an attorney for the foundation, says the searches go too far.

"Your laptop computer may contain your financial records, your e-mail with your friends and your family and your co-workers, records of the Web sites you visit, confidential business information," Hoffman says.

"Our position is there should be some suspicion of wrongdoing before the government can search your sensitive personal information at the border."

Georgetown University Law Center professor David Cole says he agrees.

"We don't allow the government to come into people's homes at will without any probable cause, without any basis for suspicion," he says. "Why should we let them get into people's computers just because they happen to be traveling across the border?"

Federal courts have given customs and border officials the authority to examine luggage for contraband, but Cole says searching an electronic device is more like a strip search because an item such as a computer can contain intimate personal information.

But how do customs agents determine which electronic devices to search?

Khan says he suspects his Pakistani roots and Muslim religion have a lot to do with it. Customs officials insist the agency does not use racial profiling but declines to say more, citing the pending legal action. For the same reason, the agency refuses to discuss what it does with the information it finds inside electronic devices.

Susan Gurley, executive director of the Association of Corporate Travel Executives, says she's concerned about the security of personal and business information obtained by customs.

"Where does it go?" she asks. "Is it shared? Is it stored? Is it destroyed? Does it go into the ether somewhere in the bowels of the U.S. government?"

Customs says its agents are law enforcement officers trained to protect private, confidential information.

However, Gurley says customs policies should be clear to the traveling public. "You should know what your rights are," Gurley says. "It shouldn't be hidden."

The federal lawsuit may provide clarification on the matter, but Cole says the issues raised may not be sorted out for years.

"The advancement of technology has left the law behind here and the law now has quite a bit of work to catch up if we are going to maintain our privacy, maintain our liberty," he says.

In the meantime, Gurley's group recommends that travelers put as little personal or proprietary information as possible on computers with which they travel.

But leaving a computer at home is not an option for travelers such as Kahn. "It's like a wallet, right?" he says. "You need your wallet everywhere you go." E-mail to a friend

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