How do you find out if the field intelligence portrayed in espionage novels or spy movies is realistic?
To find the answer, you need to look at what the characters are actually trying to achieve.
That may sound obvious, but in my experience, as soon as words like surveillance, surveillance detection, and counter-surveillance enter the conversation, the basics—goals, parameters, success metrics, and cost-benefit analysis—often get shoved into the back seat.
If you want to understand these subjects better, you have to start with the basics.
For those interested, check out this article where I break down Hollywood portrayals of covert operations.
Let’s begin with some terminology.
The concepts that come up most often are Surveillance, Surveillance Detection (SD), and Counter-Surveillance (CS). Much less frequently discussed, but far more commonly used in the real world, is what’s called Surveillance Deterrence.
Let’s break them down.
Surveillance
Surveillance can be something we conduct to gather information on a person, property or other entity. But more often, it comes up as a concern—something we suspect is being done to us. For that reason, it’s useful to distinguish between surveillance as a tool and hostile surveillance as a threat.
Hostile Surveillance
Hostile surveillance is surveillance directed against us as part of pre-attack planning. At its core, surveillance is the covert collection of information through observation.
We’re not talking about electronic surveillance here (though that can be part of it), but about a person quietly watching something or someone.
Real surveillance requires two ingredients:
- Observation
- Covertness
Take one away and it stops being surveillance. If the observation is overt, plainly visible, it’s just observation. If someone is so covert that they can’t actually see or collect information on the target, then they’re not conducting surveillance either, they’re just hiding.
Surveillance lives in the narrow, murky overlap where observation and covertness meet.
Two Ways to Deal with Hostile Surveillance
There are two broad ways to address hostile surveillance: one overt and one covert.
Let’s start with the overt one.
Surveillance Deterrence
Surveillance deterrence is about making it obvious that you’re a hard target—one that looks far less appealing than softer alternatives.
The idea is simple: project visual control over the area and actively acknowledge anyone spending time there, even if they don’t appear suspicious. This includes people passing through, loitering, or occupying nearby vantage points.
Those vantage points: windows, benches, corners, cafés, parked cars, are especially important. Identifying and plotting them is part of a process called Surveillance Mapping, typically done by a surveillance-detection professional.
Once mapped, even conventional security officers (not necessarily elite or highly trained) can be directed to:
- Visit these locations at irregular intervals
- Maintain a visible presence
- Casually acknowledge people there
- Occasionally engage them politely
The goal isn’t confrontation, it’s awareness.
A skilled surveillance operative will usually have solid cover and a plausible story, making outright exposure unlikely. Still, being seen, acknowledged, and engaged increases the chances that even a professional decides to walk away and find an easier target.
Will surveillance deterrence detect hostile surveillance? Sometimes. Lower-level surveillance often gives itself away. Higher-level surveillance may not, though. But that doesn’t mean deterrence failed. In many cases, deterrence works precisely because the hostile surveillance quietly disappears without ever being identified.
Surveillance Detection (SD)
Surveillance detection is the covert attempt to determine whether hostile surveillance is occurring, and if so, to gather basic information on it: time, location, appearance, behavior and patterns.
To spot the subtle tells of surveillance, SD operators must deeply understand how surveillance itself works. Indicators are rarely dramatic; they’re usually quiet correlations, repetitions, or small mistakes that only stand out if you know what you’re looking for.
SD must be conducted covertly—often more covertly than the hostile surveillance itself—because the person being detected may be trained. There should be no visible connection between the SD operator and the target or the target’s security team.
Think less trench coat and sunglasses, more invisible chess match.
Counter-Surveillance (CS)
Counter-surveillance only comes into play after hostile surveillance has been detected.
At this stage, the tables turn. CS involves conducting surveillance on the surveillance in order to gather deeper intelligence: who’s involved, who they work for, where they go, and what they’re planning.
Because CS may involve prolonged observation or following, it must be at least as covert as SD, and often more so.
Choosing the Right Tool
Now that we’ve covered the basics, the real question becomes: Which approach fits which problem?
The answer depends on what you’re goals are, how visible you’re willing to be, and how much time, money, and effort you can realistically invest.
From a legal standpoint, surveillance deterrence and SD generally fall under standard security work, since visible presence and visual observation don’t usually infringe on privacy rights.
Counter-surveillance, however, involves active surveillance and typically requires a private investigator (PI) license in the private sector. That’s why surveillance and CS tend to live in the intelligence and investigation world, while deterrence sits firmly in security—and SD straddles both.
One key distinction between deterrence and detection is this: deterrence is overt, so it’s less likely to uncover high-level hostile surveillance. But that doesn’t make it ineffective. Its purpose isn’t necessarily to find surveillance—it’s to prevent the attack that surveillance enables.
And that’s an important point.
Hostile surveillance isn’t the real problem. The attack that might follow is.
Most organizations would like to detect surveillance, but doing so means adding a fully covert capability, along with specialized training, logistics, and costs. That’s why many opt for the simpler, cheaper, and often more effective route: surveillance deterrence.
It may not sound as sexy as surveillance detection or counter-surveillance, but in the real world, deterrence often wins on practicality.
Another reason SD is less common is that it isn’t a solution by itself. SD only tells you whether a problem exists. If it does, you still need a follow-up plan.
So why bother with SD at all?
There are two main reasons.
First, a highly motivated and capable hostile surveillance team may push forward despite visible deterrence. In these rare cat-and-mouse scenarios, the “mouse” can actually have the advantage. If it isn’t deterred, it can adapt, relocate, and stay hidden while planning an attack.
When you suspect this level of adversary, the only way to find them is to operate covertly as well.
The second reason to use SD is lifestyle. Some people, clients, organizations don’t want to live or work inside an obvious security bubble. If overt deterrence isn’t acceptable, covert detection may be the only viable option, as long as it’s followed by whatever response the situation calls for.
Final Thoughts
This article is my modest attempt to strip away some of the mystery surrounding how surveillance, surveillance deterrence, surveillance detection, and counter-surveillance actually function in the real world.
It’s not all trench coats and car chases, but when done right, it’s every bit as fascinating.
Find out how these concepts and more play out in my espionage thriller Ghost Echo.
Learn more about these concepts and much, much more in my book, Surveillance Zone.
