Anonymous criticised Tunisia's 2012 budget (screengrab)

The Tunisian branch of Anonymous has announced Operation Revolution 404 against the government's planned measures on internet security.

In a video on YouTube, the hackers criticised the government's budget, which includes funds for hiring experts at the Ministry of the Interior to improve internet security and fight online piracy.

Anonymous urged its members to protest on 1 May against internet censorship.

"The decision threatens internet freedom, it will monitor all actions on the internet, emails, social networks, searches, absolutely everything," says the video. "It will give full powers to the government to have totalitarian control over your confidential information online.

"The [internet]) commission will probably recognise you more than your friends and family," it says.

"The commission says their aim is to formally protect against cybercrime at a national level. But the term 'cybercrime' is deliberately vague. It may refer to protections for the government, its scandals, leaks and similar cases. The government has the same reasons to censor as Ben Ali. It will be basically used to hunt you down if you criticise, especially Ennahda."

Moderate Islamist Ennahda had faced criticism from secular opponents for its alleged soft approach to conservative Salafi Islamists who are trying to impose Sharia in the country.

Anonymous recently hacked 2,725 emails belonging to Tunisia's ruling Ennahda party, including those of the prime minister, to protest against the Islamist party's failure to protect the unemployed and artists who were attacked by Salafi Islamists during a raid.

The hacktivists defaced the unofficial website of Ennahda in March to protest against the lack of progress since the fall of Zine El Abidine Ben Ali.

In the midst of Tunisa's revolution in January 2011, the collective launched Operation Tunisia, attacking government websites in solidarity with the uprising.