Other forms: freebooters
A freebooter is a looter or raider. Freebooters are pirates.
Originally, freebooters were pirates: roaming scoundrels who sailed the seas in search of spoils or plunder. In other words, freebooters robbed other ships. The term is now also used for people who steal in other settings. Freebooters, in any case, are robbers. The booty may be free for them, but they came by it through theft.