Sex shops will inundate Queensland if the Australian Federal Government filters internet pornography, an industry expert has warned.

Fiona Patten, chief executive officer of adult industry group Eros Association, said people who could not access "adult material" online would buy it from sex shops.

Queensland already had at least 116 sex shops - more per capita than any other Australian state.

"If the filtering goes ahead, Queensland will see an explosion of adult shops because, if people can't access adult material online, they'll go to retail outlets instead," she said. "Increased demand will lead to more shops."

Before the last election, the Labor Party promised to introduce internet service provider (ISP) filtering of "prohibited" material including images of sexual abuse of children.

The Labor Party promised to block content using a site blacklist that the Australian Communications and Media Authority (ACMA) maintains.

The Minister for Broadband, Communications and the Digital Economy, Stephen Conroy, said the Government was also considering more sophisticated filtering techniques to allow families to exclude additional online content from home computers.

Critics say internet filtering will be too costly, slow download speeds and threaten civil liberties.

They say children will "get around" the filters and parents will incorrectly believe their children cannot access pornography.

Keith Boswell, who runs three BeDaring Adult Shops in south-east Queensland, said some traders had complained of a downturn in business since the economic slump, while others reported business as usual.

"There is enormous demand for non-violent erotica in Queensland, so I think adult stores are probably more resilient when it comes to discretionary spending," he said.

"If the filtering goes ahead, I think some people who prefer to look online will be embarrassed to go into stores."

Protests against the proposed filters were held in Brisbane and other centres around the country on Saturday.