Passengers at a security checkpoint at Logan International Airport in Boston, August 10, 2006. REUTERS/Brian Snyder

WASHINGTON (Reuters) - The Obama administration unveiled new rules on Thursday for searching computers and other electronic devices when people enter the United States, attempting to address concerns about violating privacy and constitutional rights.

At the same time, the Department of Homeland Security defended such searches as necessary to detect information about potential terrorism plots as well as other crimes such as child pornography and copyright infringement.

“The new directives announced today strike the balance between respecting the civil liberties and privacy of all travelers while ensuring DHS can take the lawful actions necessary to secure our borders,” DHS Secretary Janet Napolitano said in a statement.

Between October 1, 2008 and August 11, 2009, 221 million travelers were processed at U.S. borders and about 1,000 searches of laptop computers were conducted, of which 46 were in-depth examinations, the agency said.

Searches often involve asking people to turn on the device to verify it is what it appears to be, the DHS said.

Privacy groups like the Electronic Frontier Foundation have pushed Congress to stop border officers from searching laptops, cell phones and other electronic devices without probable cause when people enter or return to the country.

The rules permit searches of such devices without a person’s consent. The review is to be done in the presence of the owner, unless there are national security or law enforcement reasons to conduct it elsewhere.

Immigration and customs officers can also hold the devices or the data, which may be copied without the knowledge of the owner for further review, according to the rules.

The new regulations note that border officers should be particularly careful when handling legal or business materials or other sensitive data like medical records or information carried by journalists.