Salim Osman – After surviving a mob attack over a Facebook posting, 31-year-old Indonesian civil servant Alexander Aan was taken into custody by the West Sumatra police for his own safety.

But instead of rounding up his attackers, the police charged him with blasphemy for insulting Islam and declaring that "God doesn't exist" on the social networking site a fortnight ago.

Blasphemy, which carries a five-year jail sentence, is defined under the Indonesian Criminal Code as "publicly expressing feelings or doing something that spreads hatred, abuse or taints certain religions in a way that could cause someone to disbelieve religion."

Aan may be the first self-confessed atheist who has got into trouble with the law in recent years. He was charged with blasphemy against his former religion. He was not charged with atheism.

Human rights groups deem his arrest as a violation of human rights. They have raised concerns over the rights of citizens to a religious belief. Some argue that atheism is a form of religious belief, as an atheist subscribes to moral principles that are universal and does not believe in God.

The case also raises alarm among Muslims because Aan comes from a staunchly Muslim Minangkabau region, birthplace of renowned clerics and the springboard of many Islamic movements in the past two centuries. People are outraged that one of their sons could have been misguided and turned apostate.

"He has hurt the feelings of the people in Minang society and damaged the religious structure by his posting," said the local head of the Indonesian Council of Ulama (MUI) Syamsul Bahri Khatib. "He has violated Pancasila because atheism has no place in Indonesia."

The incident has brought atheism into focus and raised the question of whether it is illegal to be an atheist according to Pancasila, the state ideology. Atheists lie low to avoid trouble with the authorities because of the notion that atheism is against Pancasila and, therefore, anathema in Muslim-majority Indonesia.

Community leaders such as cleric Syamsul Bahri invoked Pancasila's first principle which says that Indonesia shall be based on the belief in the one and only God. According to this view, atheism is a violation of the state ideology. Does this mean that atheism is illegal in Indonesia? Many believe it is.

Legal scholars see the first "monotheistic" Pancasila principle as a compromise between secular nationalist, Muslim and non-Muslim founding fathers. It resolved the decision to drop from the 1945 constitution the Jakarta Charter, whose first tenet dictates the obligation to hold Muslims to Sharia law.

Indonesian scholar Yordan Nugroho said the first Pancasila principle was not intended to ban atheism. "It was meant to bring together the different religions of Indonesia in a fair-minded, compromising manner," he recently wrote in the Jakarta Globe.

All citizens must choose one of the six recognized religions – Islam, Protestantism, Catholicism, Hinduism, Buddhism and Confucianism – on their identity cards. If atheism were to be banned, similar questions could be raised as to why three religions with no monotheistic belief – Hinduism, Buddhism and Confucianism – remain recognized in Indonesia.

Atheists like Aan are usually charged with blasphemy for defiling a religion, and not because of atheism.

The notion that atheism is illegal has its origin during former president Suharto's New Order regime, which treated atheism as an enemy of the state because, like communism, it rejects religion.

Communism was and still is considered an enemy of the state because of an alleged coup attempt by the Indonesian Communist Party in September 1965. The aftermath saw the bloody killings of thousands of communists and their sympathisers. Atheists, fearing that they would be targeted, had to declare themselves Muslims or Christians to escape death.

Since then, atheists eschew disclosing their rejection of God and all religions, for fear of being branded communists or accused of breaching the constitution and the state ideology.

However in recent years, atheists have been more assertive in proclaiming their lack of religious faith and defending their belief in no religion.

According to a recent report on atheism in Indonesia, this small community utilise tools such as blogs and Facebook groups to connect with one another. At least three social networking groups have emerged: Indonesian Atheists, Indonesian Freethinkers and the Indonesian Atheist Community.

Aan is said to be the coordinator for a new group in West Sumatra known as Ateis Minang, which has been posting pictures and comments defiling Islam on the Internet. This probably brought him and his group up on the radar.

Atheism is a fundamental right of citizens who choose not to have God in their belief systems. But atheists who want to proclaim their beliefs outside their own circles might want to think carefully before zealously taking on established religions or worse, denigrating religious faiths.