The number of phone and laptop searches by customs officials at the US border have almost doubled in the past year.

New figures released this week by the Customs and Border Protection (CBP) saw the number of device searches rise from 8,383 to 14,993 searches -- an increase of about 80 percent -- between October and March, the first six months of the agency's fiscal year.

That accounts for just under 2,500 device searches out of 31.6 million travelers on average each month, or less than 0.01 percent of all travelers who enter the country, says the agency, tasked with ensuring the admissibility of goods and people into the country.

The new numbers appear to lower earlier figures, which the agency said contained an "anomaly," referring to a system upgrade that misattributed the date.

Earlier figures published by NBC News last month suggested that this year would be a "blockbuster" for device searches, with around 5,000 device searches in February alone, according to an unnamed Homeland Security official speaking to the publication. The new border search figures point to a number less than half of that, the statistics say, but a CBP spokesperson could not explain the disparity between the Homeland Security official and the statistics.

CBP said only in its statement that it has "adapted and adjusted its actions to align with current threat information," without providing specifics.

A spokesperson for Homeland Security did not respond to our questions, including why the number of searches has risen year-over-year.

Mary Ellen Callahan, former chief privacy officer at Homeland Security, said in an email that the increase in searches is "a conscious strategy on CBP to better leverage the border search loophole," which allows border agents to search devices without a warrant.

The agency says that "no court has concluded that the border search of electronic devices requires a warrant, and CBP's use of this authority has been repeatedly upheld," but while the Supreme Court unanimously ruled in 2014 that generally a warrant must be obtained, the doctrine governing the bizarre, semi-stateless space at the US border allows agents to carry out warrantless device searches.

Device border searches remain a contentious and controversial topic, one that has piqued the interest of several lawmakers, who want to rein in that power.

Sen. Ron Wyden (D-OR) introduced the bipartisan and bicameral bill, dubbed the "Protecting Data at the Border Act," in an effort to force border agents to obtain a warrant before "thumbing through innocent Americans' personal photos and other data."

The bill, if passed, would apply to US citizens and permanent lawful residents.

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