Look, I'm not saying that people filling up and driving off without paying is a good thing.
But - from the article - the typical person filling up their car spends about $83 on it. Someone doing a runner would probably be a bit more - say, $100.
In South Australia, if the offenders came into the store and shoplifted $100 worth of goods, the police wouldn't even take the call unless you'd apprehended them in the act. It's just not worth their time for that amount of petty theft. For theft under $300, there's no jail time, and only a $300 fine.
The fact that cops _do_ tend to follow up on people not paying for petrol is the exception, not the rule.

