Sultan Hassanal Bolkiah- one of the world's wealthiest men- announced last October that Brunei would phase in sharia law punishments such as flogging, severing limbs and death by stoning beginning April 1.
The move has sparked a growing outcry on social media, the only outlet for public criticism of authorities in the Muslim country where questioning the 67-year-old sultan is taboo.
In a weekend speech, the sultan issued a clear threat to the critics.
He did not specify how social media users could be prosecuted under Islamic law.
The sultan remains a revered figure in the tiny realm of 400,000- which enjoys some of the highest living standards in Asia- and his word is unquestioned.
But in recent weeks a heated online debate has erupted in the easy-going country between sharia's supporters and those fearful of it.
Brunei has some of Asia's highest rates of Internet penetration and social media use.
Sharia punishments can include stoning to death for adultery, severing of limbs for theft, and flogging for violations ranging from abortion to alcohol consumption to homosexuality.
