Using courts to deal with problems railroad caused when it was created: you could use the Sherman

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Using courts to deal with problems railroad caused when it was created: you could use the Sherman anti-trust Act to sue monopolists for competitive practices, but that took a lot of time and money and to the extent you are dealing with too much unrestrained competition, laws that require cooperation will be less relevant.

Explain what is meant by the above bolded part and provide an example.