Limited liability has long been at the very core of their business models.. Limited liability protection for shareholders in joint stock companies was introduced to encourage investments in them. However, it has encouraged irresponsibility, causing much harm while generating profits without responsibility. Columbia Law School’s Professor Katarina Pistor has extended her critique of the legal system to emphasize the implications of such limited liability. Limited liability encourages shareholders not to pay attention to the harm corporations they invest in may do. Instead, as emphasized by Milton Friedman, shareholders should focus on returns to investment, and not be distracted by other considerations, especially the notions of corporate social responsibility and stakeholderism.