Arlina Arshad, Indonesia – To most people, Ahmad Mustofa Bisri is an influential Muslim cleric and a respected figure from the country's biggest Islamic organization, the moderate Nahdlatul Ulama.

But to his 7,000-odd followers on Twitter, the 66-year-old is Kyai Gaul, or the Trendy Cleric, who thumbs daily Islamic greetings on his iPad and BlackBerry.

Mustofa is among a growing number of Islamic leaders – conservative and liberal – who are turning to the Internet in the struggle for hearts and minds.

"I set up an account last month because I like to make friends with everyone. I don't position myself as a mufti, a religious authority. I only share what I know," said Mustofa, who is also known by his nickname, Gus Mus. "It's important for those who understand the faith to spread the word. Those who don't know, but say they do, may mislead."

Besides Twitter, he has also been preaching religious tolerance and moderation on Facebook, where he has 2,600 friends and 62,000 fans.

Islamists from hard-line groups like Hizbut Tahrir Indonesia and the Islamic Defenders Front (FPI), however, also have a Web presence, using it to advocate ancient capital punishments like stoning for adulterers.

The battle for the country's Islamic identity is just one way the Internet is transforming public debate in a country where Web usage has exploded in the past five years.

With its booming economy and burgeoning middle class, the archipelago has rapidly become home to one of the world's biggest Twitter populations, according to online research firm comScore.

Of 41 countries surveyed, it had the highest percentage of Internet users at home and work accessing Twitter in June, or more than 20 percent of its 45 million people online, comScore said.

No one who wants to be anyone – not even the stick-wielding, fringe-dwelling religious fanatics of the FPI – can afford not to have a Twitter account and a Facebook page.

And almost inevitably in a country as diverse as Indonesia, questions of faith consistently top the list of trendy topics of debate.

So-called Twitter wars are being waged on a daily basis between liberals who promote pluralism and religious tolerance, and conservatives who advocate a stern interpretation of Islam and strict moral values.

But some of the old elite are uncomfortable in the brave new world of instant communication and user-generated content.

Scandalized by the release online of the Ariel-Cut Tari-Luna Maya homemade sex videos this year, President Susilo Bambang Yudhoyono warned that the Internet "frenzy" was a threat to the nation's moral fiber.

But blogger Purwaka, known online as Blontank Poer, says the free flow of information is good for a country that only emerged from the shadow of military strongman Suharto in 1998.

"Twitter wars are good wars," the 42-year-old said. "The winner is the public. They gain a better understanding of Islam and can make their own conclusion after hearing different opinions from experts on the faith."

From homosexuality to atheism and the treatment of minorities, more people are finding they can talk about subjects online that they would be reluctant to discuss in their offices, classrooms and around their kitchen tables.

Communications Minister Tifatul Sembiring, a conservative Muslim, is one of the nation's most prolific and controversial tweeters, boasting 120,000 followers.

He drew international ridicule with a post describing how, as a pious Muslim, he had reluctantly shaken hands with US first lady Michelle Obama at a state reception in Jakarta last month.

One of his critics, liberal Muslim scholar Ulil Abshar Abdalla, tweeted to his 35,000 followers: "Enough, enough, from now on, shaking hands with non- mahrams [those unrelated by marriage] is allowed. It's halal if it's the level of Michelle Obama," he added.

IT researcher and free-speech advocate Donny Budi Utoyo said that while Muslim leaders had different views, those engaged in social networks shared an ability to cope with criticism.

"Both the liberal and conservative leaders who have joined Twitter so far seem to be open people who know how to smile. If they're attacked, they respond in a positive manner," he said. "This reflects the maturity of mind that is needed for any process of dialogue to be effective."