You need to understand that libertarians are not against mediation or even courts. If someone commits fraud, or pillages the environment, there are plenty of ways of punishing them without government. Appreciate the value of reputation.
Front-loaded prevention (ie regulation) serves as a damping mechanism against short-term maximization with irreversible consequences. A lawsuit and ruined reputation do nothing to stop the next guy.
You need to understand that libertarians are not against mediation or even courts. If someone commits fraud, or pillages the environment, there are plenty of ways of punishing them without government. Appreciate the value of reputation.