Depends on how you define pirates. We tend to conceive of pirates as free agents attacking merchant shipping fairly indiscriminately. Overall, however, this is a poor reflection of piracy in the early modern era. Pirates were typically weapons of war, sailors licensed by one nation to prey upon the merchant shipping of another nation. Such pirates are often termed 'privateers'. Both the Americans and the British made considerable use of privateers during the Revolutionary War, on both sides of the Atlantic. This was essentially legalised piracy. An American privateer could capture British ships and then sell them and their cargoes, and vice versa.