Famous Pirates throughout History. Piracy is the criminal act of hijacking, attacking or destroying a vessel on the high seas. It can often include other acts such as stealing, kidnapping, or other unlawful activities. Prior to the 1900s, privateers were privately sanctioned by the government to take over ships, usually for the purpose of acquiring goods. When privateering became prohibited, some people continued to do so illegally and thus, became pirates. Many of these law-breakers listed on this site became well-known as highly feared pirates and ruled the seas during the 1600s and 1700s.