What actions do robber barons carry out to give them this name?

Robber barons are typically associated with ruthless business practices during the late 19th century in America, where they amassed vast fortunes through monopolistic control and exploitative tactics. They often engaged in unethical behaviors such as bribery, corruption, and the suppression of labor rights. Their pursuit of wealth frequently came at the expense of competition and public welfare, leading to significant economic inequality. This combination of greed and unethical practices earned them the notorious title of "robber barons."