There are two issues at play here. The first is that, in 2006, it was deemed legal to make a backup of a "cinematograph film" for private and domestic use in an amendment to the Copyright Act. You can see the legislation here: http://www8.austlii.edu.au/cgi-bin/viewdoc/au/legis/cth/num_act/caa2006213/sch6.html
110AA Copying cinematograph film in different format for private use
(1) This section applies if:
(a) the owner of videotape embodying a cinematograph film in analog form makes a copy (the main copy ) of thefilm in electronic form for his or her private and domestic useinstead of the videotape; and
(b) the videotape itself is not an infringing copy of the film or of a broadcast, sound recording, work or publishededition of a work; and
(c) at the time the owner makes the main copy, he or she has not made, and is not making, another copy that embodiesthe film in an electronic form substantially identical to theelectronic form in which the film is embodied in the main copy.
For this purpose, disregard a temporary copy of the film incidentallymade as a necessary part of the technical process of making the maincopy.
(2) The making of the main copy is not an infringement of copyrightin the cinematograph film or in a work or other subject‑matterincluded in the film.
Dealing with main copy may make it an infringing copy
(3) Subsection (2) is taken never to have applied if the main copy is:
(a) sold; or
(b) let for hire; or
(c) by way of trade offered or exposed for sale or hire; or
(d) distributed for the purpose of trade or otherwise.
Note: If the main copy is dealt with as described insubsection (3), then copyright may be infringed not only by the makingof the main copy but also by the dealing with the main copy.
(snipped for brevity)
This is all well and good, but what if I need to circumvent an access control (namely, the Content Scrambling System, or CSS) to make this copy? Does the DMCA prevent this 2006 amendment from applying in practice, as the vast majority of DVDs are encumbered with this DRM?
This article from the Sydney Morning Herald in 2014 suggests this is the case: https://www.smh.com.au/technology/when-can-we-copy-our-dvds-20140804-1005p9.html
If it isn't legal to circumvent CSS to make a private backup, is it legal to circumvent CSS for any reason? I can't find any Australian cases about DVD ripping.