Bandung, Indonesia (CNN) -- Indonesian pop star Nazril "Ariel" Ilham was sentenced to three-and-a-half years in prison Monday for his involvement in sex videos that authorities said featured him and two other top Indonesian celebrities.
As part of his conviction under the country's anti-pornography law, Ariel will also have to pay a $28,000 fine. Prosecutors had asked for a five-year jail sentence.
He will appeal, his lawyer said, adding that there was no clear evidence that Ariel distributed the videos.
Ariel, the frontman of the rock band "Peterpan," was the first high-profile offender of the pornography law that went into effect in 2008 and carries a maximum penalty of 12 years.
The first video surfaced on several websites last year and went viral through social networking sites Facebook and Twitter. It allegedly featured Ariel and girlfriend Luna Maya -- a model and TV journalist who interviewed Hillary Clinton on her show "Dahsyat" during the U.S. secretary of state's visit to Indonesia in 2009.
After the release of the second video allegedly featuring Ariel and Cut Tari -- a soap opera star and TV journalist -- the term "Ariel Peterporn," a spin on the singer's name and his band, became a top trending topic on Twitter.
At the time, all three celebrities publicly denied appearing in the tapes, saying the people in the footage just looked like them.
The videos sparked protests by conservative Islamic groups and others around the country condemning the celebrities.
When the district court judge read the sentence in the packed courtroom Monday, hundreds of hardliners who gathered outside the courthouse booed.
"Ariel is guilty," some chanted, as about 1,000 anti-riot police personnel stood guard.
"He should have gotten at least five years," said Chep Hernawan, head of the Alliance of Islamic Movements. "We're extremely disappointed."
Noted feminist and author Julia Suryakusuma said the protests are sending the wrong message.
"This is also sending out the message that if you're loud enough, then you'll get heard and that's not the way it should be," she said.
Later Monday, the court sentenced an employee of Peterpan's music label to two years in prison.
Prosecutors said the employee, Reza Rinaldi, was the one who uploaded the videos on the Internet.