Data-driven look at America's brutal, racist debt-collection machine

I’m curious. This article does not make it clear but I presume from the tone of outrage that they are collecting debts that do not exist and that the people being taken to court do not actually owe anyone anything related to the case? Would that sum it up? That would seem to make this a fairly major case of fraud on a wholesale level

Or is there just the slightest possibility that these are legal debts someone promised to repay but has never done so? If the latter, why is this wrong? Do some people get a pass on paying back money they borrowed, money that was given to hem from someone’s pocket with the expectation of getting it back eventually.

I find I am very confused about this based on what I am reading here. If I loan someone a hundred dollars and they promise they will pay ti back to me, should I not avail myself of legal means to get that money if the person then wanders off and never pays it?