Is There a Deterrent to a Monopoly?

Lever: What deterrent would there be to Norfolk, Southern, or any other railroad giant to engaging in the same kind of behavior moving forward? Lever: I'll plead ignorance here. But are they still running freight trains on Civil War era braking systems? And by the way, like, and also transporting incredibly hazardous chemicals using brakes that are like, were, existed during the Civil War? He says it's an all-powerful situation where there's no accountability at all.