Principal Tracey Brose expelled a student. Then she found vile comments about her online.

It was late one night in March 2016, when parents of children from Tamborine Mountain State High School jumped online to discuss the school’s principal Tracey Brose.

Brose had been suspended for alleged inappropriate behaviour, but was reinstated two months later after the allegation was unproven.

Throughout her suspension, parents created a petition and private Facebook group in support of the principal.

Miguel Baluskas was convicted for unlawful damage for damaging principal Tracey Brose’s front door. He has no regrets. Post continues below video.

And while most of the online comments were complimentary, others were highly critical and abusive.

A number of parents used the forum to attack Brose, who after her reinstatement sued eight parents for defamation.

Donna and Miguel Baluskas’ son Harrison was expelled from Tamborine Mountain after making an inappropriate comment on the school bus.

The Baluskas told 60 Minutes, and earlier alleged in court, that Brose called their son a sexual predator, which she denied.

“I wrote that she’s nothing but an evil, nasty, horrible person,” said Donna Baluskas. “And she brought so much pain and suffering to our family and others.

“What she did to our son was evil.”

Mamamia’s daily news podcast The Quicky explores the rise of the new school yard bully – parents. Post continues below video.

The negative comments from some parents sparked others to share their thoughts, as well.

“It was 1.30am, I’d had a couple bourbons and I was scrolling through my newsfeed on Facebook,” Trudie Arnold said.

“There was some horrendous comments on there, like, really, really bad ones. Someone wanted her dead, some called her dreadful names, horrible. I thought ‘Oh bugger it, I’ll have a go too’.”

Arnold described Brose as “a liar, a manipulator, gets off on belittling people, is responsible for every failure at the school and is not an educator”.

She long believed Brose had ignored her daughter Madison, who had left the school two years beforehand, in favour of brighter students.

Screenshots of the parents’ comments were sent to Brose by her brother and sister.

"I was devastated. I just sat and sobbed hysterically," she recalled to 60 Minutes. "They were words meant to hurt. There was no other purpose other than to hurt me."

Brose decided to get the law involved, with a lawyer ordering the parents to apologise for their comments or face a defamation lawsuit.

Most parents did apologise, but a core group including Arnold and the Baluskas did not.

"You can tell your client to stick her offer up her arse," Miguel Baluskas said in a letter back.

The Baluskas believe the lawsuit was vindictive - and it has ended up costing them everything.

"She's out for revengence (sic) on anybody who speaks out against her. And that's all we did - we're parents who made complaints and now she's out to get us."

The Baluskas are now bankrupt. They've spent so much on legal fees, their lawyer now owns their home.

Even now, the couple refuse to apologise for their words.

Arnold and another parent, Laura Lawson, also refused to apologise, but the court ended up ruling they had not defamed Brose.

The saga has spilled out of the courts too.

In May 2018, Miguel Baluskas arrived at Brose's house at night and after she refused to engage, smashed the glass panels of her door. Brose said her three children were so scared, they ran and locked themselves in cupboards.

Asked if his 25-minute attack was "acceptable" by 60 Minutes journalist Sarah Abo, Miguel said he was just doing what he warned he was going to do.

"Yeah, you know what, what I did there was what I said I was going to do from the very, very beginning... I said 'Open the door and talk to me or I'll open the door for you'."

He was convicted for unlawful damage, but remained unapologetic.

The Baluskas have not had much luck in court: Last week, Judge Catherine Muir ordered Donna and Miguel Baluskas to each pay Brose $3,000 in damages over their posts to the Change.org petition in 2016.

Before the decision was made, the couple claimed the whole case was a conspiracy against them.

"We have just lost everything. Four years of fighting false claims, false allegations. Lost the house, lost the car, lost the caravan, been sent bankrupt by this b**** who has sent us down a trail of false claims," Donna said.

Brose has said the case was "never about the money" but to stop the harassment, which she said led to her feeling unsafe even in her own home.

"I don't need money, I don't need damages, I need [the judge] to say this isn't okay and it needs to stop. Because if she doesn't say it needs to stop, what then? Next week, they get back online and write more stuff? They're bashing at the door again? What happens to educators if we can't feel safe doing our jobs?"

Outside court, Donna Baluskas cried. Miguel spoke to media, telling reporters: "You know what, I hurt people's feelings everyday. Do you see me getting sued everyday? No."

The judge also criticised Brose, saying at times her memory was "selective". But she sees a gag order enforced on some of the Baluskas claims, stopping them from being able to repeat them, as her victory.

"I decided that I couldn't live with myself if I decided that it's okay to treat teachers that way. It's not.

"But if the attention on this case stops one teacher from going through what I have gone through, then it's all been worth it.

"You can't disrespect people and you can't abuse people. You need to be accountable if you're going to do that online."

Watch the full 60 Minutes story on 9Now.