The events of September 11, 2001 changed the way business thought about perimeter security and access control. Rather than just a barrier to keep intruders out, fences and gates are installed with protection against potential terrorist attacks in mind. Perimeter security is now being looked at to determine the best ways to stay safe.
Of course, the heightened sense of alert that followed 9-11 is only one of dozens of reasons why organizations or private residents choose to install some sort of access control. For example, Charlie Weston, president of Guardian Fence in Columbia, S.C., points out that construction sites and utilities companies have problems with people sneaking on to the property to steal copper. Prisons need good security around the property. Or it might simply be a way to monitor that the properly credentialed people are coming into a facility, like at a baseball stadium.