What arguments did progressive reformers make against trusts?

Many arguments were used against the trusts but two very general themes stand out. The first is that trusts achieved their economic dominance not because the trust operated in a business that required such dominance, but because the trusts had acquired a monopoly which allowed them to stifle competition. The second theme is that trusts, both in virtue of and in order to obtain these monopolies, exerted corrupt power on the institutions of the state, and thus subverted democracy.

Because they are harming humans