What conclusions can be drawn from the surveillance post in the barn and what questions does it raise?

The plot continues to thicken as the reader learns of the surveillance post hidden in Teabing's barn. The author does not reveal who is doing the listening--Remy or Teabing. However, because of his polio injuries, it seems likely that it is not Teabing. Also, Collet and his men discover that the surveillance equipment is set up to listen in on five different people; one of whom is Jacques. Furthermore, Jacques' office was bugged. So, that raises two questions. The first is who are the other people that were being monitored, and the second is who had access to Jacques office?