The plans have drawn an outcry from civil liberty advocates, who see it as an attack on free expression. They question whether liberal President Moon Jae-in, who was elected last year following a popular uprising that helped bring down a corrupt government, is pivoting toward a path taken by his disgraced conservative predecessors who used their powers and a criminal charge of defamation to suppress critics.
Some experts say Moon's government is becoming increasingly sensitive about public opinion as it struggles with economic and social policies and desperately tries to keep optimism alive for its fragile diplomacy with North Korea.
Seoul's Unification Minister Cho Myoung-gyon met with North Korea defector groups on Wednesday as he sought to calm criticism over his decision to block a North Korea-born reporter from covering last week's inter-Korean talks to avoid angering North Korean officials.
Presidential spokesman Kim Eui-kyeom has snapped at conservative newspapers in recent briefings for supposedly exaggerating the rift between Washington and Seoul over North Korea policies. The controversy erupted after Justice Minister Park Sang-ki last week ordered state prosecutors to aggressively chase down people spreading "false, manipulated information." He said prosecutors should be proactive in detecting fake stories and misinformation and, when needed, push ahead with criminal investigations even when no one files a complaint.
They can apply various laws, such as defamation that carries a penalty of up to seven years in prison. The Justice Ministry also plans to revise laws to make it easier to removing suspect online content.
The National Police Agency said it is currently looking into 16 false stories that made rounds online. They include claims that Moon is showing signs of dementia; Prime Minister Lee Nak-yon paid tribute to North Korea founder Kim Il Sung during a recent visit to Vietnam; North Korea has demanded cash payment of 200 trillion won ($176 billion) from the South as costs for engagement.
A frequent target is YouTube, which is overflowing with video channels run by right-wing conservatives who often make bizarre claims against a president they characterize as a North Korea sympathizer.
Park Kwang-on, a lawmaker from Moon's Democratic Party, lashed out at Google on Tuesday after it refused the party's demand to remove some 100 videos, including those describing rumors about Moon, from YouTube. Conservatives say the ruling party is pressuring a private company for political purposes.
Under Moon's predecessor, Park Geun-hye, prosecutors indicted a Japanese journalist on charges of defaming Park by citing salacious rumors about her whereabouts on the day of a ferry sinking that killed more than 300 people in 2014. Park's aides also in 2014 filed a defamation complaint against six reporters from Segye Ilbo after the newspaper reported on a leaked presidential document to allege Park was allowing a private confidante to influence state affairs.
Before Park, President Lee Myung-bak was accused of turning major TV networks into his mouthpieces by filling their corporate leadership with close supporters. They meddled in reporting and shut down investigative news programs critical of Lee's policies, triggering massive strikes and layoffs as journalists protested. Lee also took steps to strengthen online monitoring and limit the anonymity of people posting comments. Prosecutors arrested an anti-government blogger in 2009 on charges of spreading online rumors that disrupted the country's economy. The blogger was later acquitted in court.
Park and Lee are now serving lengthy prison terms over separate corruption scandals.
Moon's government has not attempted to influence the traditional media in the ways Park and Lee did. But critics say attempts to impose more rules on internet users could create a chilling effect among people and reporters criticizing and scrutinizing the government.
"We had clearly witnessed the maneuvers by the Lee Myung-bak and Park Geun-hye governments to destroy the media," the National Union of Media Workers said in a statement last week. "It's not appropriate for the government to intervene and define what fake news is. This will almost certainly create suspicions that decisions will be based on the government's taste."
Freedom of speech and media freedoms are sensitive issues in South Korea, which from the 1960s to '80s was ruled by military dictatorships that heavily censored news reports and persecuted and even executed journalists and dissidents.
The recurring debates on the boundaries of government regulation and free speech also reflect how deeply South Korea is divided along ideological lines. The arguments have mostly revolved around partisan political issues, while the country has yet to take any meaningful step to curb hate and discrimination speech against women and minorities overflowing online.
"Supporters of each side sincerely see themselves as defenders of the good against the evil, and are willing to do pretty much everything to ensure that the forces of the 'light and virtue,' that is, their side, will triumph," said Andrei Lankov, a professor at Seoul's Kookmin University.
Government officials say false stories and negative rumors have become a more serious problem than before because their influence is amplified by smartphones and chat apps.
The Justice Ministry said the crackdown targets only stories that cause "social distrust" and hurt "democratic discourse" by "intentionally manipulating objective facts," and doesn't aim against "expression of different opinions, false reports caused by mistakes, suspicions based on logic."
Legal experts say there can be no fully objective way for a government to distinguish what's maliciously false and what's simply inaccurate.
It isn't always easy to parse what's true and untrue either.
For years, Park bristled at bizarre rumors that she was allowing relatives of a late cult leader to manipulate her government from the shadows, describing them as flat-out lies. Journalists eventually proved the suspicions as true, sparking massive protests that led to Park's demise and new elections.
Lee Kang-hyeok from the Seoul-based Lawyers for a Democratic Society said the plans to strengthen government power to delete online content and bring internet users in line with traditional reporters in terms of accountability were particularly concerning.
Lee said the country's free speech is already held back by the defamation law, with charges being threatened or brought against reporters and government critics. It's also relatively easy to remove online articles, due to a law that requires websites to suspend the publishing of content deemed as false or slanderous for a month before arbitrators rule on the complaints.
SENSITIVITY OVER NORTH KOREA
Lankov said Moon's government could end up in a bitter fight with critics and conservative media if the public support of his North Korea diplomacy wanes.
Moon has garnered robust backing for his outreach to North Korea, which has resulted in three summits this year with North Korean leader Kim Jong Un. Moon also helped set up a meeting between Kim and President Donald Trump.
But Pyongyang has been playing hard ball since, insisting that sanctions should be lifted before any progress in nuclear talks, fueling doubts on whether Kim will every fully relinquish his arsenal. South Korea's enthusiasm for engagement has also created discomfort with the United States, which has called for allies to maintain pressure until the North denuclearizes.
"The Moon government has good reasons to believe (that) if it fails to create and maintain an impression of progress toward denuclearization, the U.S. hawks might use force, and this will lead to a disaster," said Lankov, who said Moon's policy is "rational and responsible" despite being possibly "dishonest" about North Korean intent.
"They are annoyed about people who tell the sad truth, since the excessive honesty might provoke a disaster," he said.