They are financed by voluntary means. One proposal that has been discussed is voluntary, nominal fees on business transactions in exchange for legal standing, for example, 0.1% to 1% of the invoice amount. Private donations (without strings attached) also play a significant role. For example, a group of businesses and individuals may pay for the development, manufacturing and upkeep of a fighter jet, submarine, or aircraft carrier, for the salaries of a local police department, or for the construction, rent and maintenance of a courthouse. A third option are lotteries where the government keeps a certain percentage of ticket sales similar to today’s Powerball.