A well-known Polish writer has been charged for calling President Andrzej Duda a "moron" on social media.
Jakub Żulczyk faces a potential three-year prison sentence if convicted of insulting Poland's head of state.
The comment in question was made in a Facebook post on November 7 following the US Presidential election, where the writer had criticised President Duda for his congratulatory tweet to Joe Biden after US media had called the election result.
Duda - a close ally of former President Donald Trump - had congratulated Biden "for a successful presidential campaign" but stopped short of recognising his victory pending Electoral College confirmation.
The tweet was posted as many other European leaders were congratulating Joe Biden, and Duda was criticised in Poland for suggesting that Biden's election victory was not definitive.
Later that day, Żulczyk accused the President of not understanding the US electoral process and stated that the Democratic candidate had clearly won.
"Joe Biden is the 46th president of the United States," he wrote on Facebook, "Andrzej Duda is a moron."
On Monday, Żulczyk confirmed that a district prosecutor in Warsaw had filed an indictment against him, based on the complaint of a private individual.
Writing on Facebook, Żulczyk said he first learned of the charges against him through the media and said he believed that he is probably "the first writer in this country in a long time to be tried for what they wrote."
A spokeswoman for the Warsaw prosecutor's office confirmed to the Polish news agency PAP that a man named "Jakub Z" had been charged.
The suspect is "accused of committing an act of public insult on November 7 last year on a social networking site against the president of the Republic of Poland using a term commonly known as insulting," the spokeswoman added.
Żulczyk - best known for screenwriting the popular TV series Blinded by the Lights and Belfer - did not admit to the offence and stated his message was a "critical assessment of the president's actions", prosecutors said.
Poland has previously been criticised for its broad insult laws, including those on offending religious feelings or insulting the flags of Poland and other countries.
However, those found guilty of charges are usually handed fines or community service as a punishment.
Joanna Szymańska is a Senior Programme Officer for Europe and Central Asia, at the organisation ARTICLE 19, that defends freedom of expression and information around the world. She says the status of free speech in Poland can be uncertain:
"There are different provisions that can be used against you if authorities want to show the rest of society that it's risky to speak out."
For now the case against Żulczyk has seen more people speaking out on social media but Szymańska says the law suit against him could have a chilling effect in the longer term - as, she believes, the government intends.
Listen to the full interview with Joanna Szymańska by clicking on the media player above.