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 is when you detect surveillance without deviating from your normal routine. Examples of passive surveillance detection include:
- Regularly checking the rear and side view mirrors while in a moving vehicle to detect surveillance vehicles following you.
- Listening to the sounds around you to detect drones or helicopters flying overhead.
Active surveillance detection is when you detect surveillance by doing something outside of your normal routine in an attempt to force a potential surveillance operation to reveal itself. Examples of active surveillance detection include:
- Taking an illogical route to travel between two points, such as a route that isn't the shortest route. If a pedestrian or vehicle takes the same illogical route as you, they may be a surveillance operator. If possible, you should have a valid reason for taking this illogical route (such as stopping at a store along the route), so that a surveillance operation doesn't notice that you are conducting surveillance detection.
- Making an unexpected U-turn while driving. If you are being followed by an incompetent surveillance team (or a single surveillance vehicle), a surveillance vehicle may mirror your U-turn, which would be a clear sign that they are following you. If you are being followed by a competent multi-vehicle surveillance team, the surveillance vehicles will not mirror your U-turn, as this would be suspicious, but your unexpected U-turn can still elicit unnatural reactions from them, which can help you to detect them. If possible, you should have a valid reason for making the U-turn, so that a surveillance operation doesn't notice that you are conducting surveillance detection.
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:
- Select a route that you will take during the counter-surveillance operation. The route should appear logical to a potential surveillance operation, 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 operation. 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 operation, but it is unlikely that anyone else would take the same route, stopping at the same stores in the same order as you.
- 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 operation). 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.
- 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 operation. 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.
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 operation.
- Surveillance Countermeasures about the principles and tactics of surveillance detection.
- The “Physical surveillance” topic.
- The related mitigation Anti-surveillance.
Techniques addressed by this mitigation
| Name | Description | |
|---|---|---|
| Covert surveillance devices | ||
| Video | An adversary can park a surveillance vehicle near your home with a camera that films your home entrance. To mitigate this, you can use the following passive surveillance detection technique. It 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. | |
| Physical surveillance | ||
| Aerial | You can conduct surveillance detection to detect most and helicopters and some drones by listening for potential helicopters and drones: you should be able to hear most of them, depending on their altitude and your surroundings. | |
| Covert | You can conduct surveillance detection to detect a covert physical surveillance operation. | |