I wonder too, especially since the propose to exercise this power overseas.

What are you wondering? What a prohibition order is? Whether they have the authority to issue one?

http://www.ministers.sa.gov.au/news.php?id=3306

It appears a prohibition order is an order against a person resultant on being around or with someone who was armed. As a result,

"A person subject to a firearm prohibition order can be stopped and searched on sight, any vehicle, vessel or aircraft of which they are in charge can be stopped and searched, and their place of residence can be inspected at any reasonable time, for firearms, firearms parts or ammunition.

Furthermore, the names of people issued with a Firearms Prohibition Order are to be made public through an online registry."

Think "sex offenders" for gun owners.

A prohibition order in Australia, Canada, or the UK is similiar to a restraining order in the U.S. I think the intent of this is to prevent gang members from associating with each other. That practice seems to be working to decrease gang violence in San Francisco.

And no alcohol either

http://my.att.net/s/editorial.dll?pnum=1&bfromind=7401&eeid=6234742&_sitecat=1505&dcatid=0&eetype=article&render=y&ac=-2&ck=&ch=ne&rg=blsadstrgt