Wow, that's pretty harsh. I have read about Australia's gun confiscation program but I didn't realize they banned possession of computer files. I wonder how that could even be enforced. What if you just rename the file to "bunny rabbit" or some other innocuous thing?
And what about 3-D printing parts of a gun separately? A barrel for example is basically a tube. Will they ban tubes? The grip is just a grip. Useful for finger strengthening. The cylinder is a candle holder. Etc.
Just piece it together and you accidentally, coincidentally have something that happens to shoot. As for bullets - hm, homemade bullets have been around for centuries. I would suspect it's possible to make bullets from scratch even in a place like Australia or Japan.
Bottom line: bans don't work, and 3-D printing merely makes it easier to circumvent clumsy, 1930s style laws.