Spread the meme. This is important.
(If you don't know what on Earth I'm talking about, have a gander at the Australian Society of Authors site. It'll fill you in.)
ETA: the email to direct your protest regarding the mailout is members (at) dymocks.com.au.
ETA: sign a counter-petition at Australian for Australian Books!
ETA: see the comments for some points to raise if anyone asks what exactly we're complaining about.
ETA: or, even better, let Garth Nix and Justine Larbalestier explain it far better than I ever could.