He has mocked Sukarno, modern Indonesia’s first president, by saying that Sukarno’s foundational philosophy of the state, known as Pancasila, put religion “up the ass.” He has made threatening speeches against Hindus in Bali. He has insulted Christians by asking, “If God had a son, then who was the midwife?”

And now he’s being charged with violating anti-pornography laws.

It’s not the first time he is in trouble with the law. In 2003, he was put in prison for seven months for insulting the police. He was sent back to jail in 2008, for a year and half, after the F.P.I. assaulted members of the National Alliance for Freedom of Religion and Faith, an interfaith group that defends the rights of the Ahmadiyah, a Muslim minority, during a convention at the National Monument in Jakarta.

But Mr. Rizieq’s latest case is a curious development.

Pornography has been an important element in his campaign to establish Islamic law throughout Indonesia. (It applies only in the northwestern province of Aceh.) Mr. Rizieq and the F.P.I. have attacked the offices of Playboy Indonesia. They have led demonstrations against Maxima Pictures for producing a film featuring the Japanese porn star Maria Ozawa, known as Miyabi. Yet Mr. Rizieq finds himself embroiled in a sex scandal, and one that mirrors another he helped create.

One day in June 2010, video footage was leaked showing the singer Nazril Irham, more commonly known as Ariel, having sex with his girlfriend and, separately, with another woman. It shocked the Indonesian public. The police soon caught two men and charged them for stealing and releasing the contents of the recordings, but much of the public outcry still fell on Ariel.

Then the F.P.I. got involved. Not only did it demand that Ariel be charged with pornography; it also said he should be stoned to death. Organizations like the F.P.I. often make their case for establishing Shariah — which calls for stoning adulterers — on the back of other issues. After a stressful trial, and riots, Ariel was sentenced to three and a half years in prison.