Laura Poitras is one of the most celebrated documentary filmmakers of our age. Her work has earned her a MacArthur Foundation "genius grant," a Pulitzer Prize, and an Academy Award. In 2013, she helped National Security Agency whistleblower Ed Snowden release classified documents to journalists.

And between 2006 and 2012, Poitras, an American citizen, was detained and questioned at airports more than 50 times. The US government has refused to explain why. So now she's suing the government to release documents related to these detentions.

Many of Poitras's detentions were much more intrusive than the "enhanced" pat-downs ordinary travelers endure at airports. On one occasion, Poitras says that her laptop, video camera, and cellphone were seized for 41 days. She would be taken to off-site locations and questioned for more than an hour. On some trips, she would be detained once before boarding a plane and then a second time upon her arrival. She says she was detained on every international trip she took between July 2006 and April 2012.

It's not hard to figure out why the government is interested in Poitras. Her journalism has consistently focused on topics that make America's national security establishment uncomfortable. She had made a 2006 film about the American occupation of Iraq and a 2010 film about two men with ties to al-Qaeda. She met with WikiLeaks founder Julian Assange during work on a film about the US state surveillance. During her work on these films, she undoubtedly talked to many people who are of interest to US authorities.

On the other hand, the United States is supposed to be a nation that protects freedom of the press and the rule of law. In most circumstances, the Fourth Amendment prevents the government from arbitrarily searching or detaining journalists or members of the general public. If an American police officer pulled over Poitras in her car, detained her for questioning, and seized all of the files on her laptop, she'd be able to challenge it as a violation of the Fourth Amendment.

But the courts have effectively stripped Americans of Fourth Amendment protections at airports and international borders. In these places, the authorities have broad latitude to detain, search, and question travelers.

Poitras's lawsuit isn't challenging the constitutionality of her many detentions. She's seeking something more basic: information. Over the past two years, she has submitted Freedom of Information Act requests to nine government agencies seeking documents related to her detention. The agencies have ignored her requests, claimed not to have any relevant documents, or refused to hand them over. So now she's suing for their release.

"I’m filing this lawsuit because the government uses the U.S. border to bypass the rule of law," Poitras said on Monday. "This simply should not be tolerated in a democracy. I am also filing this suit in support of the countless other less high-profile people who have also been subjected to years of Kafkaesque harassment at the borders. We have a right to know how this system works and why we are targeted."