Corporate social responsibility is a strategy by which firms address social issues whilst tending to their profit enhancing objectives. However, is a socially responsible firm fulfilling its objectives if current and potential stakeholders perceive it to be unethical, engaging in poor and questionable practices? The article analyzes Big Data retrieved from Twitter related to five firms that have stated to be socially responsible but have yet to obtain stakeholders' legitimacy granted by the engagement in corporate social responsibility. The article contributes to the understanding and effects of firm dynamics in corporate social responsibility or lack thereof, on social networking sites by means of Big Data analysis.