Monitoring of physical access includes publicly accessible areas within organizational facilities. This can be accomplished, for example, by the employment of guards; the use of sensor devices; or the use of video surveillance equipment such as cameras. Examples of support infrastructure include system distribution, transmission, and power lines. Security controls applied to the support infrastructure prevent accidental damage, disruption, and physical tampering. Such controls may also be necessary to prevent eavesdropping or modification of unencrypted transmissions. Physical access controls to support infrastructure include locked wiring closets; disconnected or locked spare jacks; protection of cabling by conduit or cable trays; and wiretapping sensors.