“You will be successful in banning ideas and their spread when you are able to prevent the flow of air itself.”Geoff Chambers and Sarah Crawford, “Extremist group Hizb ut-Tahrir sends veiled threat to Prime Minister Tony Abbott,” Daily Telegraph (Sydney), February 10, 2015, http://www.dailytelegraph.com.au/news/nsw/extremist-group-hizb-ut-tahrir-sends-veiled-threat-to-prime-minister-tony-abbott/story-fni0cx12-1227213869800.