Convergence Q & A: Just a Prank—or a Bigger Threat?

Q: At Halloween some students taped little black paper witches over a few indoor camera lenses. Later we found motion detection disabled on some cameras. How should we protect the cameras?


A: Camera protection requires a balance of detection and prevention, based upon the risk picture.


Camera Attack

During the “paper witch” incident, the assumption at the monitoring desk was that the black camera views meant a partial video outage—probably the intended effect. Having no other information to go on, a service call was requested from the video provider, when of course facility personnel could have quickly and easily removed the taped-up paper witches.

The loss of motion detection was a more serious issue that was not immediately discovered. It turned out to be a result of resetting the affected cameras to factory defaults. This knowledge is available on the Internet. There was no apparent hard evidence, but the assumption was that the resets were performed at the time that the cameras lenses were covered.


Camera Physical Protection

It’s not realistic to protect against all possible video loss. A good sledge hammer hit can take out a camera and unless spare cameras are available for immediate replacement, the camera’s field of view would be uncovered until new cameras were installed. The same degree of video loss would occur if a camera lens were spray-painted, unless a replacement lens was on hand. Any camera can be defeated temporarily without damaging it by simply blocking its view of the target area on.

Camera hardening features should be selected based upon the likely threats, as well as cost and aesthetic considerations.

One high school mounts its outdoor cameras on sturdy high poles to safeguard them against physical attacks, including a chain pull attack. In this instance students throw a long chain around the camera mount and try to pull the camera down. The same school has a design practice of requiring each camera be within the field of view of at least one other camera. Camera scene change detection analytics alert the school to camera shaking, as well as to lens blockage caused by spraying opaque liquids on the camera lenses. It’s the combination of the hardening and recorded surveillance measures that were effective in deterring the camera attacks.

In very low risk environments, where camera cables are run in the open without fear of tampering, there can still be accidental damage from maintenance or remodeling work, or even cleaning activity. Video systems can also be subject to technical vulnerabilities, with network and hard drive failures being two prime examples.

Thus a combination of video safeguarding measures for prevention, detection and response to video outages should be utilized. The typical manual effort of checking camera views is only partially effective in the discovery of video problems.



Vandal resistant cameras and camera enclosures are available that can be installed where cables and reset controls are not accessible without removing the camera from the wall—something that security screws can make infeasible. Other preventive measures for critical video include putting camera PoE power sources and network switches on UPS backup and emergency power, and using industrially hardened switches for harsh environments.

Lightning rods and lightning surge suppressors are appropriate for outdoor camera installations as well. In high-lightning areas, using fiber optic network cable instead of copper cable can help protect the switching infrastructure.

Running armored conduit and flexible metal conduit connectors are appropriate when cable would otherwise be exposed. In low risk areas where network cable connections are exposed, network port locking products can be used with standard switch and camera network ports. Keep in mind that these won’t stop a determined attacker from simply cutting the cable. However, they can be effective at keeping people from trying to “borrow” a network connection port, or from unplugging a cable “just for fun”.



There are both camera-based and server -based analytics for camera Scene Change Detection, which can detect a range of problems -- not just camera repositioning or view blocking. Many network cameras also have tamper alarms.

Using network monitoring software to run PING checks on network cameras will not always detect cameras malfunction, but it will detect when the network signal is off line. Enabling camera to send syslog events to a syslog server (most IT departments run or can a syslog server) will provide event messages indicating camera restarts, failed logon attempts, and other events that can indicate isolated and recurring problems.

Other network monitoring tools can be used to watch and report when the amount of video traffic on a network path drops below a level that would indicate video transmission loss.


Write to Ray about this column at Ray Bernard, PSP, CHS-III is the principal consultant for Ray Bernard Consulting Services (RBCS), a firm that provides security consulting services for public and private facilities. For more information about Ray Bernard and RBCS go to or call 949-831-6788.