This is pretty much the final act of a doomed government trying to play the National Security card against our very mildly leftish (but only Saturdays if the wind is from the Nor'Nor'East) opposition.
The puzzling thing about it, and what makes it completely pointless in my opinion, is that the technology and legislation for lawful interception is already in place (I know this to be true because I worked on it tangentially) as you would expect, and has been for quite a while.
So what this bloody thing is all about is domestic politics, not security, terrorism, or anything else of any significance whatever. And would this government chuck the Oz tech exporters under the bus for a few votes? You bet! You won't find a bigger bunch of anti-science, benighted twats anywhere except in the US, from whose Tea Party types they have cribbed their entire playbook.
To paraphrase the late, great Douglas Adams, 'Security is an illusion, National Security doubly so'.