Social network AnonPlus hacked the site at 11.25am on Tuesday, before the commission took the message down and put up a notification saying they were working to fix it.

A Victorian Equal Opportunity and Human Rights Commission spokeswoman said it was unknown why the group targeted the website.

"The reason behind today's activity is unknown," she said.  "No demands have been made to the Commission."

The manifesto made little sense with sentences such as "every person who has the goodwill to act is welcome".

"AnonPlus spreads ideas without censorship, creates spaces to spread directly through mass defacement, publish news that the media filtered and managed for the consumption of who controls, we do that to restore dignity to the function of the media: media should be free, without censorship and must limit itself to 'show what's happening' and don't 'say to us what's wrong and what's right'," the message said.

"AnonPlus puts offline sites that actively contribute to the control of the masses from the corrupt, that by manipulating information and opinions create false realities: this is censorship!

"AnonPlus not act for personal or political causes, has no leaders, loves to the interests of the people and we will fight until the leadership and powership will lead into the hand of people unique owner of the free world."

The message said no data was "stolen or deleted" in the hack.

"Only home page was chanced [sic]. We are not criminal, we are AnonPlus."

The commission's spokeswoman also said no privacy breach had occurred as personal data was not held on the site.

She said it was the first time the site had been hacked.

Fairfax Media has attempted to contact the group via its Twitter account.