Prosecutors did not like the idea that a player could put money into a machine and then sit back and wait until the machine, or another computer, decided if the player had won. The latest twist came with the realization that winning bingo cards did not have to be displayed as bingo cards. Linking electronic bingo terminals within a hall allows the game to be fast and more secure. Paper pull-tabs have evolved in a similar manner. Vending machines can dispense the pull-tab, which can show symbols like a slot machine and be imprinted with a bar code.
Machine now come with bar code readers.
Regulators have approved the game, because the slot machine part is completely unnecessary.