Electronic Frontiers Association (EFA) chair Dale Clapperton said the problems encountered by senators are indicative of what will happen if the technology is mandated nationally.

"Hopefully the senators run-ins with mandatory filtering will caution the government."

Spokesperson for Senate leader Alan Ferguson said the changes bring the Senate in line with other government departments and agencies which have content filtering.

"The Senate Appropriations and Staffing Committee considered Internet filtering and noted all departments have content filtering and decided senators should not be treated any differently," he said

"The report was agreed to by the Senate and the technology was applied. It wasn't applied unilaterally; there was committee consultation."

The content filter, reportedly from Websense, uses a blacklist to block access to "illicit" content. Users can contact parliament helpdesk to clear false-positives and gain access to blocked sites.

The changes were pushed by Family First senator Steve Fielding 12 months ago when he described the unrestricted Internet access of parliament as a "workplace that peddles porn".

Communications Minister Stephen Conroy announced the plan for mandatory national Internet content filtering in January, on the premise of fighting child pornography.

The Electronic Frontiers Association (EFA) has launched a Web site, dubbed No Internet Censorship for Australia, to inform users of the privacy concerns the technology raises.

The Web site labels the plan a technical disaster, and reports the content filters will require a "massive expansion" of the Australia Communication and Media Authority's blacklist of prohibited content, will block legal material, and will instill a false sense of security to parents of the dangers of the Internet.