Hostage, a person held in captivity to assure that an agreement is observed or to coerce another party into taking (or not taking) some action. Countries in ancient and medieval times sometimes exchanged hostages, often persons of high rank, who could be put to death if certain agreements were broken. Invading armies often take hostages of local citizens to discourage resistance to their occupation. Terrorists sometimes seize hostages both to force concessions from governments and to gain publicity for their cause.
In their own vision of themselves, Yakuza descend from Robin-Hood-like characters who defended villages from bandits. Today, they operate as a collection of criminal gangs.
Ever wonder why you've been called for jury duty four times while your friend has never got a summons? Are you on some secret list of the "ready and available"? We'll give you the scoop.