Surveillance detection

Contents

Surveillance detection is the practice of detecting if you are under physical surveillance, that is, detecting if you are being directly observed by an adversary. There are two types of surveillance detection: passive surveillance detection and active surveillance detection. Counter-surveillance is a sophisticated form of active surveillance detection.

Passive surveillance detection

Passive surveillance detection is when you detect surveillance without deviating from your normal routine. Examples of passive surveillance detection include:

Active surveillance detection

Active surveillance detection is when you detect surveillance by doing something outside of your normal routine in an attempt to force a potential surveillance effort to reveal itself. Examples of active surveillance detection include:

Counter-surveillance

Counter-surveillance is when you detect surveillance with the help of a trusted third party (i.e., one or more people) who is presumably not under surveillance, and who attempts to detect if you are under surveillance. The following is an example of a counter-surveillance operation:

  1. Select a route that you will take during the counter-surveillance operation. The route should appear logical to a potential surveillance effort, but should be illogical for anyone else to take, and should include several stops that are suitable for the third party to attempt to detect a surveillance effort. For example, you can start at your home, stop at three or four hardware stores in your city pretending to price a certain item, and return to your home. This route would appear logical to a potential surveillance effort, but it is unlikely that anyone else would take the same route, stopping at the same stores in the same order as you.
  2. As you follow the selected route, the third party ensures that they are present at each stop before you, but without taking the same route as you (so they won't detected by a potential surveillance effort). To accomplish this, the third party can use a faster mode of travel than you, or leave each stop before you to get a head start, or use multiple coordinated teams.
  3. At each stop, the third party takes note of pedestrians and vehicles arriving after you. If the third party notices that a pedestrian or vehicle is present at two or more stops, they may be part of a surveillance effort. The third party can also detect behaviors typical of surveillance operators, such as transmitting information through a radio hidden on their body, communicating with each other through visual signals, running unexpectedly, etc.
Additional considerations

If an adversary notices that you are conducting surveillance detection, they may adapt and become more discreet. Therefore, when conducting surveillance detection, you should avoid revealing that you are doing so, if possible. If you successfully detect surveillance, you should avoid visibly acknowledging or evading the surveillance effort.

See also

See the physical surveillance topic and the related mitigation Anti-surveillance.

Techniques addressed by this mitigation

NameDescription
Physical surveillance
Aerial

You should be able to see and hear most helicopters and some drones, depending on their altitude and your surroundings.

Mobile

You can use surveillance detection to detect a mobile physical surveillance effort.

Covert surveillance devices
Video

A specific passive surveillance detection technique can help you detect a surveillance vehicle parked near your home and equipped with a camera pointed at your home. This technique only works if you live in a place where there aren't too many different vehicles that park, that is, in some residential areas in cities and in most rural areas. Each time you leave or enter your home, you take note of all the vehicles parked on the street that have a line of sight to your home. Trying not to look suspicious, you note their model, color, and license plate number, either remembering the information or writing it down. After doing this for a while, you will become familiar with the “baseline” of vehicles that park on your street, which will be the vehicles of people who live nearby or their guests. Once you're familiar with the baseline, you'll be able to spot vehicles that are not part of that baseline and discreetly examine them to see if they are surveillance vehicles.