I dont think this is quite what gives ethics officers problems. The main problems with contacts are mostly from outside of work where private friendships are cherished more that serving the citizens, and it becomes rational to shortcut the system. The fact that many contractors and lobbyists cultivate these friendships intentionally for business purposes and shortcuts are taken to expedite profits can be readily seen in the Gulf Spill we are watching.
Enlarging public participation will create more transparency. In fact the computer is creating more transparency too. Beware to Crooks! What is unknown today is found out tommorrow. Either technology gets better; more information comes into the system; or somebody discovers them accidentally.