Security for a power over ethernet installation

Aspects of the present invention monitor an electrical circuit in a power over Ethernet ("PoE") installation to detect potential security breaches and implement a security response upon detecting the security event. The security event may be a disruption to the electrical circuit lasting more than a threshold duration (e.g., 250 ms, 0.5 second, 1 second). The disruption can be an open circuit caused by cutting or unplugging the Ethernet cable. In one aspect, the security response can be discontinuing further communications over the PoE connection.