Facility control methods and apparatus

A security system comprises:

• a physical sensor configured to determine presence of a first plurality of users within a detection region;
• a reader device disposed within the detection region, wherein the reader device is configured to output presence signals to a plurality of smart devices associated with a second plurality of users, wherein the reader device is configured to receive a plurality of ephemeral ID signals from the plurality of smart devices, wherein the plurality of ephemeral ID signals are not permanently associated with the second plurality of users, wherein the reader device is configured to output reader identification signals to the plurality of smart devices, wherein the reader device is configured to receive responsive signals from the plurality of smart devices in response to the reader identification signals, wherein the responsive signals are not permanently associated with the plurality of smart devices, wherein the reader device is configured to determine a plurality of authenticated users in response to the responsive signals;
• a physical device configured to provide a physical output that can be sensed by security personnel;
• a processing unit coupled to the reader device and to the physical sensor, wherein the processing unit is configured to receive the plurality of authenticated users from the reader device, wherein the processing unit is configured to receive the presence of the first plurality of users, wherein the processing unit is configured to determine a tailgating condition in response to the plurality of authenticated users and in response to the presence of the first plurality of users, wherein the processing unit is configured to direct the physical device to provide the physical output in response to the tailgating condition.