This is why I believe that end-to-end encryption is not truly useful unless the source code of the clients is public, or the protocol is open.
Any closed source client can read messages at the ends, or be forced to do so by an evil government.
At the very least, they could open up XMPP compatibility again so that people could write their own open source clients for it. Australia wouldn't be able to do anything about the propagation of such open source software.
I was able to have end-to-end encryption running on top of MSN, AOL, ICQ, QQ, Facebook, Gtalk, Yahoo, and several others about 10 years ago with Pidgin and simple plugins that encrypted/decrypted messages on the fly. It's too bad they all moved selfishly to closed source walled-garden mobile apps -- it's a big step back in privacy.