A Christian man in Indonesia was sentenced to four years in jail after a court said he insulted the Muslim prophet Muhammad in a Facebook post.

On Tuesday, Martinus Gulo, a 21-year-old university student, was found guilty of Islamic blasphemy by the Medan District Court, The Christian Post reported.

Gulo was arrested in March after an Islamic organization reported his activities to police, Rappler reported. The man said he published his posts in response to posts that criticized Christianity. 

He was charged under the Information and Electronics Transactions law, a controversial statute that many claim has been utilized to imprison Christians and other religious minorities in Indonesia, which has the world’s largest number of Muslims.

Gulo was also fined one billion rupiahs (US$69,000) and if he fails to pay the fine an additional six months will be added to his jail term.

The case showed Indonesia’s blasphemy laws can easily be exploited by radical groupsInternational Christian Concern Regional Manager Gina Goh said in a statement.