Among all threats to maritime security, today piracy is certainly the most famous of them. Following a series of unprecedented violent attacks, the international community sent a military fleet off the coast of Somalia in 2008 to restore order and security. However, given the significant costs of such device, some legal scholars have not hesitated to support a greater use of the private sector in the fight against piracy. To achieve this, the resurgence of letters of marque, which allowed, during the past centuries, the practice of privateering, was proposed. This attempt to use the privateers against these threats is not devoid of legal issues regarding their conformity with modern international law. Far to dismiss the relevance of a greater use of private sector, the author underlines the need for a permanent mechanism in which companies will contribute to current and future naval presences. After establishing the terms of use of letters of marque by States, the author suggests the establishment of a partnership between public and private sector whose terms will remove all risks inherent to the use of private military companies.