In democratic South Korea, you're free to express your opinion on most topics — except North Korea. Korean-American Shin Eun-mi learned that lesson the hard way. After a few tourist trips to the North, she shared her observations of North Korean people, landscape and culture in two books and several speeches in the South.
"I said, 'North Korean beer tastes good, and the water of North Korean rivers is clean,' " Shin said in a phone interview.
That's how she crossed the line in the eyes of South Korea's government. Police launched a month-long investigation into Shin's allegedly pro-North Korean comments.
"I was deported with no re-entry to South Korea for five years. The charge is that I violated the National Security Act of South Korea," Shin explains.
Prosecutors ultimately didn't indict her, but she hasn't been allowed to return to her birth country since immigration officials deported her early last year.
The National Security Act is a controversial law that's been on the books since the founding of South Korea in 1948. Lawmakers intended it to prevent communist ideas from creeping in from the Soviet-backed North. In Article 7, the law prohibits "praising, encouraging, or propagandizing" on behalf of North Korea. But it doesn't specify exactly what that means. Shin says it's overly broad.
"If anyone says something good about North Korea even though the statement is true, he or she can get into big trouble in South Korea," Shin says.
She's filed suit to try to get her travel ban lifted. But the law casts a net far beyond Shin Eun-mi. More than 100 were arrested under the law in 2013, doubling the total number of arrests in 2006. South Koreans have been snared for seemingly small offenses, like retweeting a message from pro-North Korean accounts.
Just weeks ago, censors blocked a British journalist's website that covers North Korean technology, for allegedly violating the law. The National Security Act is used as justification for censorship of the South Korean Internet, where users are blocked from visiting any North Korean or North Korean-sympathetic sites.
The issues underline a long-running tension in the South: how to balance hard-fought freedoms with keeping its citizens safe.
"We need national security law, and also we need freedom. So how to harmonize is very important," says Suh Suk-koo, an attorney and former judge who oversaw national security cases. A self-described conservative, he supports the law as it's written.
"North Korea violated the armistice agreement so many times. [That is the] kind of critical, dangerous situation here in South Korea. Therefore it is necessary for us to apply national security law in case of [North Korea] overthrowing our democratic, constitutional system," Suh says.
The paradox, say critics, is that to protect its democratic ideals, the South's government behaves more like its undemocratic neighbor.
"Why do they fear a debate of ideas when it's quite clear that most North Korea, if given the chance, would try to find a way to South Korea," says Phil Robertson, deputy Asia director for Human Rights Watch.
"I would say that more than 60 years since the end of an all-out war, it's ridiculous to claim that praising North Korea or advocating Pyongyang's policies constitutes a real threat to South Korea's national security," Robertson says.
Human Rights Watch and other similar groups have been calling for a repeal of the law or a re-writing of the controversial Article 7. The United Nations has said that same vague section shouldn't exist. The U.N. Special Rapporteur on the Rights to Freedom of Peaceful Assembly and of Association recently brought it up again following a January visit. The U.S. State Department has said it is "concerned" the National Security law limits freedom of expression.
Shin Eun-mi — who's still not allowed to return to South Korea — says her case won't be the last.
"As long as the National Security Act exists, this kind of instance will happen again and again," Shin said.
As tensions with the North ratchet up, tensions within South Korea simmer.
Haeryun Kang contributed to this story.