Best graffiti I ever saw was painted on a bridge in Melbourne.
Some one had painted “ New Zealand sucks.”
Underneath someone else had painted in different paint “ Australia nil.”
I found a Melbourne bumper sticker ('85) amusing: “Grow your own dope” it said, “Plant a Pom”.
Incidentally, I did not sink the Rainbow Warrior. I was in Wellington that week. Got the see the tip of the mast sticking up out of Auckland harbour the following week.