Why, you may ask? Because they thanked Julia Gillard for the carbon tax:
Fremantle thanks Gillard for carbon tax
Prime Minister Julia Gillard has been showered with praise by Fremantle residents for her government’s proposed carbon tax during a community cabinet meeting in the West Australian port city. But that was to be expected at Australia’s only carbon neutral high school in a state electorate held by a green independent MP. On Wednesday night Ms Gillard chatted with people wearing T-shirts calling for action on climate change and posed for photos in front of a banner which read: ‘Thank you for the carbon tax’. (source)
Stupidity knows no bounds where the Greens are concerned.