The use of safety nets within the ATM system has been established for many years. The scope of safety nets has extended to be not only airborne based but ground based as well. There is a move to extend their application into other areas such as an ATM tool, often with a view to a reduction of separation. Also, the concept of separation protection as opposed to collision avoidance has been introduced. This implies that the controller is alerted when the separation minima are about to be infringed and action will be taken to maintain the minima. In this case, the use of the safety net is being compromised by its use as conflict detection tool.