Perceptions of the Islamic Defenders Front (FPI) sank even lower in the eyes of the Indonesian public last month when a spokesman for the hardline group threw a glass of water at a university professor during a debate on a morning talk show aired live on private television network TVOne.

The show, which aired June 28th, was discussing what kind of steps the police would take this year to prevent vigilante groups from conducting vice raids during Ramadan. National Police Spokesman Boy Rafli Amar was one of the guests via videolink.

FPI spokesman Munarman and University of Indonesia Sociology Professor Thamrin Amal Tomagola were seated side by side on a sofa in the studio, flanked by the hosts of the show "Apa Kabar Indonesia Pagi," when a testy discussion on the topic took a .

After Thamrin commented that political alliances could make it difficult for local leaders to rein in hardline groups, Munarman insisted at length that groups take matters into their own hands because police don't enforce existing regulations.

When Thamrin tried to interject and defend his point, Munarman seized a glass of water, dashed it in the older man's face, and leapt to his feet, saying, "Shut up! You shut up when I am talking."

The broadcast quickly cut away, but clips of the exchange flooded YouTube, and social media lit up with outrage over the outburst. Religious leaders joined in condemning it.

A bad example for Muslims

Nahdlatul Ulama (NU) Nuril Arifin Husein told reporter that Munarman should not present such a combative attitude because he is an example for his followers.

"Maybe Munarman is not yet ready to be an Islamic leader," he told Khabar Southeast Asia. "He will not be a leader if he is not able to control himself."

"It was an embarrassing attitude, but you know, it shows the real face of FPI. They could not respect other people's opinions," said Husain Maghbrib, an Islamic cleric in Jakarta. "I do not think FPI is standing for its name, 'Islamic Defenders Front'. Looking at their attitude, are they defending Islam? As a Muslim, I feel like he is simply defending himself."

Meanwhile, Hendardi, chairman of the Setara Institute for Democracy and Peace, said Munarman's action was inappropriate for a democratic society.

"In democracy, no matter whether we agree or disagree during a debate or discussion, we must appreciate the opinion," he told Khabar. "Munarman's actions are a reflection of his organisation, which always imposes its views on others."

An affront to free speech

In a statement on its website, the Indonesian Legal Aid Foundation (YLBHI) asked TVOne to apologise to the public and refrain from inviting guests like Munarman on air. It even encouraged Thamrin to take legal action against the FPI spokesman.

"Munarman's violent action threatens free speech and democracy in Indonesia. This action not only affects Thamrin Amal Tomagola, but it also potentially caused public fear," the statement read.

Many people urged Thamrin to report Munarman to the police, but the sociologist declined to do so, noting that a top police official witnessed the incident first hand.

"Let the public judge, and give appropriate social punishment," he tweeted after the show. "I don't want to respond to thugs."