A court in Myanmar has sentenced a young poet to six months in jail for defaming former president Thein Sein, making him one of the first political activists sentenced since Nobel peace prize laureate Aung San Suu Kyi took power in April.

Maung Saung Kha, 23, used his Facebook account to publish a poem about having a tattoo of a president on his penis. He was charged for defaming Thein Sein under telecommunications laws, used to curb free speech in several other recent cases.

Because Maung Saung Kha has spent more than six months in jail since being arrested, he will be freed on Tuesday.

But the case highlights the limits of control that Aung San Suu Kyi’s government, elected in November on pledges of democratisation, has over the government where the military plays an outsized political role.

It also draws attention to a continued use of the telecommunications law to stifle dissent.

Enacted as part of an opening up of the telecoms sector in 2013, the legislation bans use of the telecoms network to “extort, threaten, obstruct, defame, disturb, inappropriately influence or intimidate”.

“I’m glad I can go home freely, but I’m disappointed about the verdict,” said Maung Saung Kha after leaving the court.

“Even though we have a democratically elected government, the verdict was like from the old days.”

The judiciary in Myanmar has for decades been an instrument of oppression by the junta against democratic opposition activists, many from Aung San Suu Kyi’s party, jailing them for long terms on show trials.

Despite Suu Kyi’s victory in November, the military-drafted constitution guarantees it control over the home ministry, which oversees the courts. It also controls two other security ministries and controls 25% of seats in the parliament.

Last year, NGO worker Patrick Kum Jaa Lee was sentenced to six months in jail for commenting on a picture showing a foot standing on a photo of army chief Min Aung Hlaing. Several more people were charged under the same law this year.

Aung San Suu Kyi’s government released scores of political prisoners shortly after taking power, but 64 people remain behind bars and 138 are awaiting trial for political actions, according to the Assistance Association for Political Prisoners, a watchdog.

It is unclear whether the NLD plans to reform the telecommunications law or how far it intends to change other opperesive laws from the military era.

Human rights advocates raised alarm that its draft of a revised law regulating public demonstrations keeps many military-era curbs on free speech.