Given the .au TLD, I assume this is an Aus-based instance, and therefore will need to comply with it, legally. Obviously it might be possible to just stay under the radar and not get caught, but the approach aussie.zone is using is a pretty good one, mostly relying on circumstantial evidence like “the person remembers a cultural event from the '80s” or “a photo of the back of someone’s head while driving, with their username displayed on it”.