18. The computer implemented method of claim 17 , further causing the non-transitory programmable device to undertake the step of outputting a representation of the sixth data if the user request is from the first intended recipient.
18. The computer implemented method of claim 17 , further causing the non-transitory programmable device to undertake the step of outputting a representation of the sixth data if the user request is from the first intended recipient. 19. The computer implemented method of claim 18 , wherein the step of causing the non-transitory programmable device to undertake the step of deriving the sixth data includes the step of causing the non-transitory programmable device to undertake the step of deriving the sixth data in response to receipt of a further user request.