Al-Watan online daily said today that religious police in charge of monitoring social networks found more than 600 objectionable tweets.
It says the 28-year-old man admitted to being an atheist and refused to repent, saying that what he wrote reflected his own beliefs and that he had the right to express them.
The report did not name the man.
The court also fined him 20,000 riyals, about USD 5,300.