More than 80 activists packed a Brisbane university classroom on Monday night, hoping to build on a social media campaign against the Federal Government's proposed internet filter.

Last week federal Communications Minister Stephen Conroy announced the Government would move ahead with plans to force all ISPs to block "Refused Classification" material.

The material would include sites on overseas servers containing child sex abuse, bestiality, sexual violence or detailed information about how to use drugs or commit crimes.

Activists argue the blacklist will also include material that should be accessible to adults, such as pornography that is legal to possess in Australia, and information about topics such as abortion and euthanasia.

They say the Government should cancel plans for the mandatory filter and focus on giving parents advice on how to supervise their children online.

Following the Minister's announcement, hundreds of comments were left on the ABC website, most condemning the move.

The "#nocleanfeed" hashtag, which was used on Twitter posts opposing the filter, became one of the most popular topics discussed on the social networking site that afternoon.

Many Facebook users are also supporting the campaign, with the "Stop mandatory filtering of Australian internet" protest page counting more than 10,000 fans.

But Senator Conroy shows no signs of backing down, and says he intends to introduce the legislation to Parliament in the first half of next year.

New approach

The organiser of the Brisbane protest meeting, Nicholas Perkins, says news of the gathering spread through word of mouth and sites like Facebook and Twitter, attracting a broad group of participants.

"We're getting support from stereotypical geeks to everyday computer users, as well as students who may not be on the internet a lot but need to use it for research," he said.

Speakers called for a new approach to fighting the filter, describing poorly attended street marches in 2008 as "embarrassing".

"This is not the time to be making fools of ourselves," Nic Suzor from lobby group Electronic Frontiers Australia (EFA) told the meeting.

His organisation is advocating an online protest in January that would see websites and social media sites turning black.

He says a similar "internet blackout" about copyright laws in New Zealand successfully pressured the government there to reverse changes to legislation.

Youth disenchantment

Michael Meloni, 25, says the movement is getting attention from people who might normally be politically disengaged.

He has started a campaign to deliver a stocking of coal to the Minister for each 1,000 letters he gets opposing the filter.

"I think it's damaging the way young people look at Labor," he said.

"It won't change much now in terms of seats, but it's not something people our age will forget."

ABC elections analyst Antony Green agrees it would be unusual for a single issue like this to have much impact on the outcome of a federal election.

"The big difference in Australia is we have compulsory voting," he said.

"With voluntary voting, online campaigns can motivate people to vote. So narrow campaigns built around online activism aren't nearly as effective here because you have to change people's votes rather than get them to show up."

While Australian elections do tend to be decided by younger voters, Mr Green says he is not convinced the internet filter is an issue which is having a big impact.

"Swing voters tend to be people voting on economic issues - people who don't pay too much attention to politics," he said.