An example: girl meets boy at a nightclub and decides she wants further contact with him, but doesn't know him well enough to give him her mobile or home number. She simply dials 087 123 43283 from her mobile and is given a new dating number, which she gives to the Boy. She can now fully control where that number is routed. If things go well she can give him her private mobile or home number at some future time. If things don't go well, she can simply disconnect the number to avoid any further contact.