The law would have allowed police to fine people protesting over the nutty Vatican's nutty stance on issues such as women's rights over their fertility and anyone's rights over what he or she does with his or her choice portions and dangly bits.
The ruling, says this BBC story, comes at the opening day of World Youth Day, which Pope Ratzo will be attending later this week.
The challenge to the law was brought by a coalition of protest groups.
Activists say they plan to hold a rally on Saturday at which they will demonstrate against the Church's stand on homosexuality and birth control, by handing out condoms and wearing provocative T-shirts.
Civil liberty groups had denounced the New South Wales state law – which threatened fines of up to A$5,500 (£2,680) against anyone causing "annoyance" to pilgrims – as unnecessary and repugnant.
Quite right. There are, one assumes, laws to deal with unruly behaviour that don't involve blatant censorship. No one's suggesting that the world and its uncle should gather in NSW and heckle every Catholic, but there must be a right to protest when huge swathes of people can see the Catholic Church for the evil that it is capable of.
Anyway, once such a law is put in place, it's anyone's guess as to how the police will interpret it, and, once the event is over, it's too late to seek redress against them, because the damage to free speech will have been done.