Phone phreakers had discovered a way to make free phone calls, taking advantage of a flaw in some types of "diverters"—devices that were used to provide call forwarding (for example, to an answering service) in the days before call forwarding was offered by the phone companies. A phreaker would call at an hour when he knew the business would be closed. When the answering service picked up, he would ask something like, "What hours are you open?" When the person who had answered disconnected the line, the phreaker would stay on; after a few moments, the dial tone would be heard. The phreaker could then dial a call to anywhere in the world, free—with the charges going to the business.