Judges slam attacks on Monis magistrate

Threatening the magistrate who granted Man Haron Monis bail is helping "the murderer" achieve his aim of dividing society, the Judicial Conference of Australia says.

Magistrate William Pierce granted Monis bail last December while he was facing charges of being an accessory to his ex-wife's murder.

Monis's then partner, Amirah Droudis, 34, has been charged with her killing.

Mr Pierce said at the time the crown's case was weak and the pair did not represent a threat to the public.

Since this week's siege at a Martin Place cafe, Mr Pierce has been attacked on social media, with various users posting "you unleashed this dog," "shame on you" and "you should resign" on Twitter.

People have also blamed Mr Pierce for the deaths of two hostages.

But Federal Court judge and the president of the Judicial Conference of Australia, Justice Steven Rares, said Mr Pierce was doing his job "honestly and in good faith, as we all would expect".

"The murderer will achieve his goal of dividing our society if the lives of judges and magistrates are threatened because they do their jobs as best they can," he said.

Retired Victorian Supreme Court judge Bernard Teague said those who criticised Mr Pierce needed to consider the circumstances of the case.

"I'm very familiar with the (bail) process and the difficulty of the process and the stupidity of people coming and making these kinds of threats to the person who has to make those difficult decisions," he told AAP.

The president of Muslims Australia, Hafez Kassem, has also urged people to stay united.

He said Muslims should not be blamed for the actions of Monis, whom he described as a renegade.

"Let us not be like this individual to create division amongst us all," he said.

"As a Muslim leader in Australia, I condemn the action by the perpetrator who did not represent the Muslims or Islam."