Members of hacktivist group, Anonymous, have released some of the 40GB of data that was taken from internet service provider (ISP) AAPT's compromised server last week.
The data, which was posted online on the Par-onia website early on Monday morning, includes documents showing federal government accounts, information from departments such as the Australian Federal Police (AFP) and names of AAPT staff members.
According to Anonymous, the group also has files showing details of AAPT customers but has promised to remove sensitive customer information from the leaks to protect individuals.
The group released the information as part of a campaign against the Australian Government's proposed data retention laws which are currently under discussion by the Parliamentary Joint Committee on Intelligence and Security (PJCIS).
In addition, a video by Anonymous Australia justifying the data release was posted online over the weekend.
The transcript accompanying the video:
"Dear citizens of the world, we are Anonymous. AAPT is Australia's third largest land line telecommunications company and is a wholly owned subsidiary of Telecom New Zealand. The company is a member of the Infrastructure Assurance Advisory Group for the Critical Infrastructure Protection branch of the Attorney-General's department.
"In the past few years the rise of censorship and filtration of freedom of speech has been on the rise. Our very own governments surveying the very same people who voted and put you, the government, in a position of power and trust.
"Australia, you have failed us! Now expect us!
"Australia ranks highly in many international comparisons of national performance, such as quality of life, health, education, economic freedom, and the protection of civil liberties and political rights. Yet Australia feels the need to censor and filter every day social and personal life?
"What are you afraid of? Who or what are you protecting?
"We, the people, feel disgusted from this decision based upon power, money, and greed.
"We will not sit around as we have big brother watching us from all angles and eyes pointed at everyone.
"Did you ever think who and what will be affected by your selfish acts?
"Anonymous is taking a stand and will fight for the unjust!
"Welcome to #opAustralia. We decided to give you a taste of your own medicine... A total of 40 giga bytes has been obtained using the very same techniques used on the Australian population.
"We as people have the right to protest in any way shape or form to get our voices heard. Let this be the first warning!
"Keep the people happy. You keep the population happy...... we can move on from this!
"Till then, expect us."
Meanwhile, Melbourne IT confirmed on Friday that it was investigating the data breach which affected its customer, AAPT, and reported that the incident was isolated with only a small number of servers affected.
Melbourne IT chief executive, Theo Hnarakis, told CIO Australia that the incident was related to a specific vulnerability which only affected a small number of servers.
"We believe this was an isolated incident however we are treating the matter extremely seriously and are undertaking multiple additional scans across our entire infrastructure base which includes a large number of servers," he said.
Follow Hamish Barwick on Twitter: @HamishBarwick