BANGKOK (AP) — A Thai court sentenced a human rights lawyer to 16 months in prison on Wednesday, finding him guilty of sedition for material he posted online but dropping charges of royal defamation.

Prawet Prapanukul had been indicted on 10 royal defamation charges and three sedition charges. He has said he would not appoint a lawyer to defend himself in the case he called "a political issue, not a legal one."

The Ratchada Criminal Court in Bangkok sentenced him to five months for each sedition count and an additional month for refusing to let officials take his fingerprint identification, Thai Lawyers for Human Rights said.

Prawet had been a lawyer for supporters of the former Prime Minister Thaksin Shinawatra, who was ousted by a military coup in 2006. He was arrested last year in connection with material he had posted on Facebook about Thailand's 1932 revolution, which turned the country from an absolute monarchy into a constitutional one. Thailand's current military government declared safeguarding the monarchy a top priority.

Critics of the lese majeste law covering royal defamation, which carries a punishment of three to 15 years' imprisonment, say it is used to silence political dissidents. The legal aid group said last week at least 162 people have been charged under the lese majeste law since the military seized power again in 2014. Prawet's was a rare case of an acquittal.

According to the group, at least 92 people have been prosecuted for sedition-like offenses.

"Prior to the 2014 coup, the 'sedition' offence was used infrequently. In contrast, the article has become one of the most used tools of the NCPO to restrict freedom of expression," their report said. The ruling junta is officially known as the National Council for Peace and Order, or NCPO.

The government has often targeted people for their online activities, including simply sharing or reposting material originating elsewhere. Last year a court sentenced a prominent student activist to 2½ years in prison for sharing a BBC article about the country's new King Maha Vajiralongkorn Bodindradebayavarangkun on Facebook.

The junta became particularly sensitive to anti-monarchist sentiment following the death of revered King Bhumibol Adulyadej in 2016 and the succession of Vajiralongkorn. Thais' devotion to the monarchy was shaken by the political turmoil that followed the 2006 coup against Thaksin, whose political popularity was seen as a challenge to the country's establishment.

In 2017, Thai authorities declared it illegal to exchange information online with three prominent government critics who live outside Thailand and often write about the monarchy.