A passenger plane approaches to land at the JFK airport in New York on October 11, 2014. The airport started health screenings for travelers arriving from Ebola-hit West African nations on October 11, as the death toll from the deadly virus topped 4,000. Passengers arriving from Liberia, Sierra Leone and Guinea will have their temperatures taken, be assessed for signs of illness and answer questions about their health and exposure history, the US Centers for Disease Control and Prevention (CDC) said. AFP PHOTO/Jewel Samad (Photo credit should read JEWEL SAMAD/AFP/Getty Images)
JEWEL SAMAD/AFP/Getty Images/File
A passenger plane approaches to land at the JFK airport in New York on October 11, 2014. The airport started health screenings for travelers arriving from Ebola-hit West African nations on October 11, as the death toll from the deadly virus topped 4,000. Passengers arriving from Liberia, Sierra Leone and Guinea will have their temperatures taken, be assessed for signs of illness and answer questions about their health and exposure history, the US Centers for Disease Control and Prevention (CDC) said. AFP PHOTO/Jewel Samad (Photo credit should read JEWEL SAMAD/AFP/Getty Images)
Now playing
01:25
WH mulls screening foreigners' social media
President Donald Trump addresses the 73rd session of the United Nations General Assembly, at U.N. headquarters, Tuesday, Sept. 25, 2018. (AP Photo/Richard Drew)
Richard Drew/AP
President Donald Trump addresses the 73rd session of the United Nations General Assembly, at U.N. headquarters, Tuesday, Sept. 25, 2018. (AP Photo/Richard Drew)
Now playing
01:17
Trump to migrants: Make your nations great again
Central American immigrants depart ICE custody, pending future immigration court hearings on June 11, 2018 in McAllen, Texas. Thousands of undocumented immigrants continue to cross into the U.S., despite the Trump administration's recent "zero tolerance" approach to immigration policy.  (Photo by John Moore/Getty Images)
John Moore/Getty Images
Central American immigrants depart ICE custody, pending future immigration court hearings on June 11, 2018 in McAllen, Texas. Thousands of undocumented immigrants continue to cross into the U.S., despite the Trump administration's recent "zero tolerance" approach to immigration policy. (Photo by John Moore/Getty Images)
Now playing
01:06
Judge blocks asylum seekers from deportation
Pool
Now playing
01:51
Trump: I prefer shutdown before midterms
CHICAGO, IL - JUNE 29:  Demonstrators hold a rally in the Little village neighborhood calling for the elimination of the U.S. Immigration and Customs Enforcement (ICE) and an end to family detentions on June 29, 2018 in Chicago, Illinois. Protests have erupted around the country recently as people voice outrage over the separation and detention of undocumented children and their parents.  (Photo by Scott Olson/Getty Images)
Scott Olson/Getty Images North America/Getty Images
CHICAGO, IL - JUNE 29: Demonstrators hold a rally in the Little village neighborhood calling for the elimination of the U.S. Immigration and Customs Enforcement (ICE) and an end to family detentions on June 29, 2018 in Chicago, Illinois. Protests have erupted around the country recently as people voice outrage over the separation and detention of undocumented children and their parents. (Photo by Scott Olson/Getty Images)
Now playing
01:30
HHS refusing to release family separation stats
Now playing
01:01
Reporter to Sarah Sanders: Why did Trump lie?
Now playing
01:28
Trump: ICE agents are mean but have heart
Pool
Now playing
01:23
Trump: Our facilities better than Obama's
trump king of jordan visit
CNN
trump king of jordan visit
Now playing
01:15
Trump: No regrets signing executive order
Immigrant children walk in a line outside the Homestead Temporary Shelter for Unaccompanied Children, a former Job Corps site that now houses them, on Wednesday, June 20, 2018, in Homestead, Fla. (AP Photo/Brynn Anderson)
Brynn Anderson/AP
Immigrant children walk in a line outside the Homestead Temporary Shelter for Unaccompanied Children, a former Job Corps site that now houses them, on Wednesday, June 20, 2018, in Homestead, Fla. (AP Photo/Brynn Anderson)
Now playing
01:54
Children in limbo after Trump executive order
Secretary of State Mike Pompeo listens as President Donald Trump speaks during a cabinet meeting at the White House, Thursday, June 21, 2018, in Washington. (AP Photo/Evan Vucci)
Evan Vucci/AP
Secretary of State Mike Pompeo listens as President Donald Trump speaks during a cabinet meeting at the White House, Thursday, June 21, 2018, in Washington. (AP Photo/Evan Vucci)
Now playing
02:18
White House chaos over immigration reversal
Watched by Homeland Security Secretary Kirstjen Nielsen (L) and Vice President Mike Pence, US President Donald Trump signs an executive order on immigration in the Oval Office of the White House on June 20, 2018 in Washington, DC. - US President Donald Trump on Wednesday signed an executive order aimed at putting an end to the controversial separation of migrant families at the border, reversing a harsh practice that had earned international scorn."It's about keeping families together," Trump said at the signing ceremony. "I did not like the sight of families being separated," he added. (Photo by Mandel Ngan / AFP)        (Photo credit should read MANDEL NGAN/AFP/Getty Images)
MANDEL NGAN/AFP/Getty Images
Watched by Homeland Security Secretary Kirstjen Nielsen (L) and Vice President Mike Pence, US President Donald Trump signs an executive order on immigration in the Oval Office of the White House on June 20, 2018 in Washington, DC. - US President Donald Trump on Wednesday signed an executive order aimed at putting an end to the controversial separation of migrant families at the border, reversing a harsh practice that had earned international scorn."It's about keeping families together," Trump said at the signing ceremony. "I did not like the sight of families being separated," he added. (Photo by Mandel Ngan / AFP) (Photo credit should read MANDEL NGAN/AFP/Getty Images)
Now playing
02:49
What's next after Trump's policy reversal?
Trump meeting 06202018
POOL
Trump meeting 06202018
Now playing
02:33
Trump reverses position on family separations
President Donald Trump signs an executive order to keep families together at the border, but says that the 'zero-tolerance' prosecution policy will continue, during an event in the Oval Office of the White House in Washington, Wednesday, June 20, 2018. Standing behind Trump are Homeland Security Secretary Kirstjen Nielsen, left, and Vice President Mike Pence. (AP Photo/Pablo Martinez Monsivais)
Pablo Martinez Monsivais/AP
President Donald Trump signs an executive order to keep families together at the border, but says that the 'zero-tolerance' prosecution policy will continue, during an event in the Oval Office of the White House in Washington, Wednesday, June 20, 2018. Standing behind Trump are Homeland Security Secretary Kirstjen Nielsen, left, and Vice President Mike Pence. (AP Photo/Pablo Martinez Monsivais)
Now playing
01:52
Trump signs executive order to end family separations
CNN
Now playing
01:18
Trump: Take children away to prosecute parents
THE PRESIDENT meets with the National Space Council  In-House Pool (Pre-set 9:30AM | Final Gather 11:15AM -- Palm Room Doors)
Pool
THE PRESIDENT meets with the National Space Council In-House Pool (Pre-set 9:30AM | Final Gather 11:15AM -- Palm Room Doors)
Now playing
01:40
Trump: The US will not be a migrant camp

Story highlights

Katie Fallow: Many citizens re-entering US subjected to cellphone searches and questions about their social media

Knight First Amendment Institute is suing to see government data on how, when, why, on whom this is being practiced

Editor’s Note: Katie Fallow is a senior attorney at the Knight First Amendment Institute at Columbia University. The opinions expressed in this commentary are hers.

(CNN) —  

An engineer from NASA’s Jet Propulsion Laboratory. A Wall Street Journal reporter and a French-American photojournalist. An independent filmmaker. An electronics salesman.

These are some of the many American citizens re-entering the country who have been subjected to searches of their cellphones and questioning about their social media.

Katie Fallow
Courtesy Katie Fallow
Katie Fallow

Such invasions of travelers’ private communications are extremely intrusive and have been conducted even when officials don’t apparently have reason to think the person has done something wrong. And the government has lately increased the practice dramatically — even though recent legal decisions raise serious questions about its constitutionality.

Because people keep ever more of their personal details on their phones and computers, it is particularly egregious that the government should claim some right to unfettered access to these devices simply because a person travels abroad.

On Monday, the Knight First Amendment Institute at Columbia University — whose mission is to defend free speech in the digital age — filed a lawsuit seeking to compel the government to release information on the number of travelers whose devices have been searched, the policies related to searching cellphones containing sensitive and confidential information, and the findings of internal audits about the device search program.

Border searches of electronic devices by the Department of Homeland Security have risen exponentially in recent years, from about 5,000 device searches in 2015 to about 25,000 in 2016, according to press reports that cited DHS data. During the Trump administration, the intrusions appear to have become even more frequent; in February 2017 alone, border officials searched 5,000 devices.

And why is this happening? A US Customs and Border Protection policy since 2009 authorizes officers to seize and search a traveler’s electronic devices even if the person is not suspicious. The policy was always legally dubious, but it has become indefensible in light of the Supreme Court’s 2014 landmark decision in Riley v. California.

The court held that police generally can’t seize a person’s cellphone as part of an arrest without first obtaining a warrant that is backed by evidence that the cellphone contains evidence of a crime and is signed by a judge.

A cellphone contains “the sum of an individual’s private life,” Chief Justice John Roberts wrote for the court. The search of a smartphone is nothing like the search of a duffle bag. What people store on their cellphones – including Internet browsing history, medical records, family photos, GPS location data, financial information, and apps related to dating, addiction and hobbies – is vastly more sensitive than what people used to carry in their pockets, backpacks, or purses, or even keep in their homes.

Searches of electronic devices when there is no basis for suspicion to search them raise serious concerns relating to the freedoms of speech and association. As Justice Sonia Sotomayor observed in another recent Supreme Court case, “[a]wareness that the government may be watching chills associational and expressive freedoms.” Americans will be justifiably concerned about speaking freely if, simply because they travel internationally, the government is given unlimited authority to read through their emails, texts, social media posts and the like.

The implications may be especially significant for a free press. Suspicionless searches of cellphones threaten the ability of journalists and their sources to report on important international issues, which deprives the public of its right to know about those issues.

Numerous reports show that journalists, lawyers and activists — particularly those who cover civil wars and terrorism or travel to conflict areas — have had their cellphones and devices searched at the US border, where officers have demanded their passwords and read their communications with sources.

Those sources will likely be leery of sharing information with journalists and activists if their identities and reports may be revealed to the US government at the border.

Anecdotal evidence about how the government is using its authority to conduct suspicionless electronic device searches is disturbing but incomplete. The public has a right to see a fuller picture, as many civil liberties groups have asked the government to provide.

Our freedom of information lawsuit request seeks a range of information, but one of the items we seek may be especially revealing: We’ve asked for the database of the Treasury Enforcement Communications System that houses information about every device-search at the border, including the reason for the search, the country of origin of the traveler, and the traveler’s race and ethnicity.

The government created this database in response to concerns voiced by the Department of Homeland Security’s civil rights office several years ago about the possibility that searches might be conducted in a discriminatory or otherwise unlawful way.

Disclosure of the database — perhaps with narrow redactions to protect legitimate national security and privacy interests — would help the public understand the answer to basic questions about the government’s program: How often do border officers search travelers’ cellphones and other devices, and for what reasons?

Why did the incidence of cellphone searches sharply increase in the past 15 months? Does the department follow its own rules for taking special measures to protect searches of privileged and other sensitive content stored on cellphones, and what are those rules?

The courts should require the government to disclose this information and quickly, and the practice of delving into travelers’ private lives at the border without reason to suspect them of wrongdoing should ultimately end. Everything we know about the government’s searches of devices at the border suggests the government is dramatically expanding an unconstitutional program.