What makes a pirate a pirate and not a privateer? Well here's the difference. One is sanctioned by their respected government, given Letters of Marque and they do not attack ships from their own country. The other harasses anyone who passes by, takes no prisoners and gives no quarter. Throughout history there are examples of privateers crossing the line from legitimate to illegal, and unless their home country was in the middle of delicate negotiations with the enemy, the home countries tended to ignore such lapses in morals.
One significant difference between Pirates and Privateers were the Articles of Piracy . Though pirates were lawless, they lived by a certain set of codes. The articles were drawn up by the crew, and everyone would then sign the contract that bound the ship together. The following is an example of the Articles of Piracy. These were the articles used by the ship Revenge which was commanded by Captain John Phillips.
Article One - Every man shall obey civil command; the captain shall have on full share and a half in all prizes. the Master, Carpenter, Boatswain, and Gunner shall have one share and quarter.
Article Two - If any man shall offer to run away, or keep any secret from the Company, he shall be marroon'd with one bottle of powder, one bottle of Water, one small Arm, and shot.
Article Three - If any Man shall steal any Thing in the Company, or game, to the value of a piece of Eight, he shall be Marroon'd or shot.
Article Four - If at any Time we should meet at another Pyrate that man shall sign his Articles without Consent of our Company, shall suffer such Punishment as the Captain and Company shall think fit.
Article Five - That a man that shall strike another, whilst these Articles are in force, shall receive Moses's Law (that is 40 Stripes lacking one) on the bare Back.
Article Six - That Man that shall snap his Arms, or smoak Tobacco in the Hold, without cap to his Pipe, or carry a candle lighted without lanthorn, shall suffer the same Punishment as in the former Article.
Article Seven - That Man that shall not keep his Arms clean, fit for an Engagement, or neglect his Business, shall be cut off from his Share, and suffer such other Punishment as the Captain and Company shall think fit.
Article Eight - If any man shall lose a joint in time of Engagement, shall have 400 Pieces of Eight: if a limb, 800.
Article Nine - If at any time you meet with a prudent Woman, that Man that offers to meddle with her, without her Consent, shall suffer Death.
They tended to live a warped version of profit-first democracy, and in no way did pirates like authority. Contrary to the book Treasure Island, most Captains didn't command by an iron fist, they commanded because of skill, daring, and the ability to win prize and booty. The Pirate ship elected its Captain through a vote. If the Captain fell in disfavor the crew were just as quick to maroon their captain, or throw him overboard, or perhaps if he were lucky they would just let him off at the nearest port.