Brisbane bus drivers are given DNA kits to track down expectorators?

Seriously, what is the point of this? Okay so let’s assume your typical bus driver knows how to use a DNA kit. I assume they are just collecting a sample of spit to send off to a lab for PCR-based testing and not doing it at home in their own labs. But then what? To the best of my knowledge (?!) my DNA isn’t on file with any of the authorities. So what good will it do them? If I *do* get caught in the future for a crime, and I’m DNA tested at the time, they will be able to say "hah! you also owe us $50 for spitting on a bus!"???

Or is this a pre-cursor of a day in the near future when we’ll be subjected to a swab every time we want to ride on public transport in Brisbane?

What’s next? Taxi drivers scraping semen stains off of the back seat and turning up on my doorstep? Imagine if Travis Bickle had one of those?