In addition to implementing a carbon tax, Australia is proposing a law that would force cigarettes to be packaged in plain boxes. About 75% of the new boxes would be covered with graphic warnings about the effects of smoking, leaving much less space for trademarks and such. Unsurprisingly, the tobacco industry intends to sue.
Nearly 100 years ago US law established a doctrine of "clear and present danger" to describe the situations in which the right to free speech might be abrogated. My best reading of Wikipedia tells me that in 1969 the standard was changed to ban only incitements to "imminent lawless action." Obviously Australian legal proceedings will proceed from a different background, but the question is intriguing: if tobacco consumption is legal but expensive to the state, can governments limit advertising?