A big problem here is, what is the airline's incentive for the list to be accurate? If it has a whole lot of false positives, in absolute numbers it's still too

A big problem here is, what is the airline's incentive for the list to be accurate? If it has a whole lot of false positives, in absolute numbers it's still too small to put any real dent in their business - there are millions and millions of other customers. What you really need is transparency, oversight, an appeals process, and guarantees that human judgement is in the loop - all things that come "for free" with the court system, but would have to be recreated from scratch in any corporate-run extrajudicial penalty system.