South Korea is trying to ease worries about online privacy after a domestic chat app lost customers to a foreign rival because of fears prosecutors can get access to online conversations.
Prosecutors last month launched a cyber-investigation team after President Park Geun-hye spoke out against online rumours that she said "crossed the line" and were deepening divisions in society.
But that has sown confusion and fear of snooping among users and providers of online services.
On Thursday, Prime Minister Chung Hong-won tried to reassure the public about online privacy, saying the government would only seek monitoring rights in special circumstances, such an investigation of murder, human trafficking or insurrection.
"(He) emphasised that the government has been steadfast in ensuring freedom of expression and other basic privacy rights and will continue to do so," Chung's office said in a statement.
Authorities insist they have no intention or ability to conduct large-scale surveillance of the public but South Korean messaging app KakaoTalk said it had lost users because of the fears about surveillance.
A rival German app, Telegram, which does not have servers in South Korea, added more than two million Korean users in the two weeks through to 11 October, according to market researcher Rankey.com.
Telegram rushed out a Korean-language version in response to the surge in business.
"The defection to a foreign app reflects hostility towards the government," said Sohn Dong-young, a media professor at Hanyang University.
Daum Communications Corp, KakaoTalk's operator, said on Monday it had stopped complying with monitoring warrants since 7 October to protect KakaoTalk user privacy.
It also shortened the time it keeps data on servers and would introduce privacy modes, making it nearly impossible for third parties to see user conversations, it said.
"We will introduce real-time monitoring devices if that becomes a legal responsibility of operators," Daum co-chief executive Sirgoo Lee said at a parliamentary hearing on Thursday. "But today this decision is for the operators to make, and we have no intention of doing so."
South Korea is a vibrant democracy but until 1987 it was an authoritarian state, with tight restrictions on freedom of expression and widespread surveillance.
That history makes South Koreans especially sensitive to any encroachment on freedom of speech, said Sung Dong-kyoo, a professor at Chung-Ang University's department of mass communication and journalism.
"We have rapidly transitioned from being a tightly controlled society, and react more sensitively about ensuring the protection of privacy," Sung said.