Maritime security operations are the actions of modern naval forces to "combat sea–based terrorism and other illegal activities, such as hijacking, piracy, and slavery, also known as human trafficking." Ships assigned to such operations may also assist seafaring vessels in distress.Maritime security operations (MSO) are the actions of modern naval forces to "combat sea–based terrorism and other illegal activities, such as hijacking, piracy, and slavery, also known as human trafficking." Ships assigned to such operations may also assist seafaring vessels in distress.Maritime security is concerned with the prevention of intentional damage through sabotage, subversion, or terrorism. Maritime security is one of the three basic roles of the United States Coast Guard has gradually developed in response to a series of catastrophic events, which began in 1917.