Facebook on Tuesday blocked access within Thailand to a group that has criticized the country's king but said it was planning a legal challenge to the government's demand that it restrict access to the organization's page.
The move comes amid near daily youth-led protests against the government and unprecedented calls for reforms of the monarchy, in a country that has experienced decades of protests punctuated by military coups. Thailand's strict lese majeste laws forbid "defaming, insulting or threatening" the king or royal family, and carry penalties of up to 15 years in prison.
"Facebook has determined that we are compelled to restrict access to content which the Thai government has deemed to be illegal," a Facebook spokesperson told NBC News in a statement.
"Requests like this are severe, contravene international human rights law, and have a chilling effect on people's ability to express themselves."
The "Royalist Marketplace" Facebook group, which counts around 1 million members, was created in April by Pavin Chachavalpongpun, a self-exiled academic and critic of the monarchy.
On Monday night, the group's page brought up a message: "Access to this group has been restricted within Thailand pursuant to a legal request from the Ministry of Digital Economy and Society."
Pavin, who lives in Japan, told Reuters that Facebook had bowed to the military-dominated government's pressure.
"By doing this, Facebook is cooperating with the authoritarian regime to obstruct democracy and cultivating authoritarianism in Thailand."
Pavin created a new group of the same name, which already had over 455,000 members as of Tuesday according to Reuters.
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Facebook said on Tuesday it was planning to legally challenge the Thai government after being "compelled" to block access to the group.
"We work to protect and defend the rights of all internet users and are preparing to legally challenge this request," a spokesperson said. Facebook said it would ask the court to decide on the legality and constitutionality of the government order relating to the group, but did not give details of a time-frame.
Thailand's digital ministry last week filed a separate cyber-crime complaint against Pavin for creating the group.
Earlier this month, more than 10,000 Thai protesters chanting "down with dictatorship" and "the country belongs to the people" rallied in Bangkok, in by far the biggest anti-government demonstrations since a 2014 coup.
Demonstrators were calling for curbs to the monarchy's powers, as well as demands for the departure of former junta leader Prime Minister Prayuth Chan-ocha, a new constitution and an end to the harassment of opposition activists. Many held up three-fingers, mimicking a salute from the Hollywood movie the "Hunger Games," during protests.
Anger has further been fueled by accusations of corruption, the arrest of some student leaders over earlier protests and the economic fallout from the coronavirus epidemic.
Some student groups have also presented 10 reforms they seek to the monarchy of King Maha Vajiralongkorn, including curbing his powers over the constitution, the royal fortune and the armed forces.
Reuters contributed to this report.