I have a soft spot for Tariana Turia. Yes i know she's a bit of a nutbar but...she's not afraid to express points of view that sometimes challenge or upset the status quo. Sometimes these can be silly and not very well thought through; other times, her observations are quite insightful and perceptive.
There used to be an absolutely brilliant piece of graffiti-work at the Morningside Station (in comic-book/cartoon form) depicting the dangerous effects of "P." Of course, this piece of graffiti-work was completely unauthorised. However, it undoubtedly had artistic merit, was an expression of street culture, and at the same time it conveyed an important social message, in a powerful way.
The Council of course painted it over - now you can look at a blank wall instead while waiting for the train.

The Council failed to paint over much less worthy tagging all over other parts of the station.