There is a current push to have lane filtering specifically endorsed in the Australian Road Rules. While there are no specific laws against the practice there are many associated road rules that make the practice very expensive if applied by the officer in the jurisdiction within which you are riding.
The MRA ACT recommends reading the attached link and if you agree “sign” the petition.
http://www.gopetition.com/petitions/define-and-legitimise-motorcycle-filtering.html
