The Ultimate Guide to Counter Surveillance Devices
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The Ultimate Guide to Counter Surveillance Devices

It’s uncomfortably easy for someone to get their hands on hidden cameras, covert audio recorders, and discreet GPS trackers. While there are legitimate reasons for people to use these devices for their own security, this equipment can just as easily be used by abusers, stalkers, and other unsavory people.

Modern surveillance equipment can be so small or so cleverly disguised that it’s extremely difficult (or even impossible) to detect with the naked eye. And that’s what makes counter-surveillance equipment so valuable: it sees and detects what you can’t.

But just as there are different types of surveillance equipment, there are different kinds of counter-surveillance devices. Some counter-surveillance gear is designed to detect cameras, audio recorders, or trackers. Others sabotage any equipment in the area and render their recordings useless. Some audio recorders and hidden cameras use radio frequencies or wifi signals to transmit data. Others don’t. The type of equipment you need completely depends on the kind of device you’re trying to counter.

If you’re trying to detect more than one type of device—or you aren’t sure what you’re trying to detect—you may need to invest in more than one piece of tech. 

(Note: counter-surveillance equipment isn’t cheap. You can easily spend several hundred dollars for quality devices.)

Maybe someone has been referring to things you said or did when they weren’t around. Or they keep “running into you” in suspicious situations. Or maybe you want to make sure you have privacy in your next AirBnB. 

Whatever your reasons, we’re going to walk you through everything you need to know about counter-surveillance devices—so you can put your suspicions to rest. In this guide, we’ll explore the main types of counter-surveillance equipment, and we’ll dig into anything else you should know about surveillance or counter surveillance.

Types of counter-surveillance equipment

When it comes to types of counter-surveillance equipment, there are a couple things to keep in mind:

  1. What kind of devices can it detect?
  2. What kind of monitoring can it prevent?

Your counter-surveillance gear could use a powerful radio frequency (RF) detector . . . but if a hidden camera or audio recorder isn’t using a RF, it’s not going to detect those devices. You’re more likely to run into this with devices someone would check manually, like a hidden audio recorder or hidden camera with built-in storage.

It’s also worth noting: there’s a lot of variability with equipment that detects counter-surveillance devices. Some may simply confirm there’s a device “in the area,” while others can pinpoint exactly where that device is.

Depending on your situation and your concerns, you may want to detect a device so you can remove it, or you might just want to prevent it from recording you, or transmitting what it records.

Unless you know exactly what kind of device you’re trying to find, you probably want to choose a piece of equipment with multiple capabilities. They’re pricier, but it’ll always provide better security than a device that’s only built to detect one type of surveillance equipment.

RF detector

A radio frequency (RF) detector is one of the more versatile counter-surveillance devices you can buy. It’s designed to pick up nearby devices uses electromagnetic wave frequencies, including audio recorders, cameras, and GPS trackers. It only detects devices that transmit an RF signal within a specific range of frequencies (or “bands”). 

If an RF detector doesn’t pick anything up, that doesn’t necessarily mean nobody is recording you—it just means nobody is watching live. Or, they may be using a device with a signal outside your range (or a device that doesn’t transmit a signal). A good RF detector should pick up multiple bands and help you rule out many devices—particularly devices that don’t require someone to physically access them.

Radio frequencies are measured in hertz (Hz). Most communication devices transmit between 3 megahertz (MHz) and 6 gigahertz (GHz). Typically, surveillance equipment that transmits data uses cellular, Blu-tooth, or wifi signals, which generally fall under these ranges:

  • GPS tracking devices: 824–846 MHz, 880–920 MHz
  • Cellular transmissions: 824–894, 1850–1990
  • Bluetooth transmissions: 2400–2480 MHz
  • Wifi transmissions: 2400–2480 MHz

So if your RF detector only detects frequencies up to 2400 MHz, for example, you’ll miss devices that transmit via Bluetooth or wifi. Similarly, some devices only detect devices within 2.4–6 GHz, or over 6 GHz, so they miss devices that transmit using lower radio frequencies—including analog equipment. Some types of counter-surveillance devices (like wiretap detectors and GPS detectors) are just specific forms of RF detectors: they’re designed to pick up the frequencies used by specific types of devices.

Unless someone is actively listening or watching live, the surveillance device might only transmit intermittently. A GPS tracker, for example, might be set to transmit data at fixed intervals, and you may need to keep your detector on for a few minutes before you pick up a signal. And a hidden audio recorder or camera may be voice or motion activated, so it won’t transmit unless there’s something “worth transmitting.”

In addition to the bands your RF detector can pick up, you need to pay attention to the physical range it can detect within. Some may only work within a few feet, while the best can pick up signals from 40 feet away or more and allow you to home in on the device.

Advanced RF detectors may also allow you to use the signal a surveillance device is transmitting—meaning you can jump into the video feed or playback the audio. With video, this can help you find the device itself.

Pro tip: when using an RF detector, you should turn off any known devices that produce an RF signal. Your RF detector probably isn’t going to tell you exactly what device you’re picking up—just what kind of signal it is. So you don’t want to waste time checking against your computer, phone, tablet, gaming system, Alexa, smart home devices, and other equipment you aren’t worried about.

Wiretap detector

There are several ways someone can wiretap your phone, but a lot of them depend on the type of phone you use.

If your smartphone takes a long time to turn off, the battery gets hot when you’re not using it, or it dies fast despite being new, that could be a sign someone has tapped your phone with a hidden app. With smartphones, “detecting a wiretap” can sometimes be as simple as identifying a suspicious app. But other wiretaps involve physical devices which can be installed on almost any piece of the phone itself, including the charger. 

Landlines work completely differently. Your landline is on a circuit. When you add another landline to your home or office, you break that circuit to add the new line. This is essentially what someone is doing when they wiretap your landline, and there are several methods someone may use to listen in. 

They could essentially just add another phone on your circuit, but this requires them to know when you’re on the phone so they can listen in (they’d also need to mute their end so you don’t hear them breathing). 

They could also use an audio recorder (likely with voice activation), which works more like your answering machine. But then they’d need to physically access the device to charge it, replace the battery, or access the recording. 

Or they could install a bug, which transmits the audio from the phone line using a radio frequency. In this case, an RF detector that picks up low bands is effectively a “wiretap detector.”

But there are other tapping techniques people can use to eavesdrop on your calls. Unfortunately, not all of them are detectable. (Since someone just has to break your circuit, they can do it further “down the line” where you don’t have access.) More sophisticated wiretap detectors can identify some other taps that don’t rely on RF signals, but in most cases, an RF detector will do the trick.

Camera finder

When a camera isn’t transmitting a signal, your RF detector isn’t going to see it. But that doesn’t mean you’re out of luck. “Camera finders” (also known as lens finders) use infrared light or LEDs to pick up the reflection from a lens. In theory, you could try to use any bright light and look for a reflection, but a quality lens finder will have some sort of display (or even a lens you look through) to help you identify the glow of a lens.

GPS detector

A GPS tracker has to use an RF signal. It communicates with satellites to acquire location data, and in most cases, it’s going to transmit that data as well. So if it picks up frequencies in the right range, an RF detector is effectively a GPS detector.

To pick up GPS devices, you’ll want an RF detector with a range of 800 MHz to 2 GHz. Just remember, a GPS device probably won’t be set to constantly transmit, so you’ll have to be patient as you check for them. Depending on the interval it transmits at, you may have to wait several minutes to detect a signal.

Some GPS detectors are powerful enough to locate a GPS tracker even when it’s off.

Microphone blocker

People don’t need RF bugs to use your smartphone or computer against you. Hackers can tap into your microphone to pick up audio even when you’re not using your device. If you can’t find anything obvious (like a suspicious app you don’t remember installing), but you’re concerned someone is spying on you, you may want to get a microphone blocker. These devices plug into your headphone jack and disable the microphones on your phone, tablet, or computer—so no one can pick up your audio.

Audio jammer

Audio jammers are far from discreet, but they’re an effective way to ensure your conversations are completely private. They work by projecting either white noise or “noise masking acoustics.” Some generate noise directly in the area you’re having a conversation, and others attempt to essentially create a wall of sound around you. The best audio jammers project sounds in a variety of frequencies to ensure any recording of your conversation will be useless, and they produce sound at a loud enough volume to drown out your conversation if anyone happens to be listening in the moment.

The challenge is to find an audio jammer that strikes a balance between preventing anyone from spying on you and allowing you to actually have your conversation. Some high-end audio jammers come with noise cancelling headsets, so you can communicate clearly while the jammer masks your audio.

Counter-surveillance apps

Believe it or not, your smartphone is actually capable of becoming a counter-surveillance device. Whether you have an iPhone or an Android, there are apps to turn your phone into an:

  • RF detector
  • Camera finder
  • Microphone blocker

Of course, you often get what you pay for, and RF detector apps in particular are rampant with fake or ineffective apps. But since your phone already has a camera and screen, it can pretty easily become a decent camera finder. (Here’s a decent app for Android and for iPhone.) And it makes an even better microphone blocker. A good microphone blocker app can also list apps on your phone that have recording capabilities and identify other threats. (Here’s one for Android. Unfortunately, iPhones don’t get one.)

And remember: some hidden cameras and audio recorders act as wifi hotspots, so someone can tune in with a mobile device. Your phone, tablet, or computer can help you discover if there’s a device in your home or office by detecting strong wifi signals that don’t belong.

Use your eyes, too

Once you know what to look for, you might be surprised how often a well-trained eye can spot surveillance devices. 

Hidden camera lenses are small and discreet, but they’re usually still visible if you look closely. And many surveillance devices have to plug-in somewhere. So look for suspicious wires. When you turn out the lights at night and walk around the room, do you see any lights that might be produced by a hidden camera with night vision? Does anything look out-of-place? Do you have any duplicate devices, or electronics you don’t recognize? Has your furniture been moved, as though someone used it to reach a high shelf?

The more familiar you are with how cameras and audio recorders are installed (and how they can be disguised), the easier it will be to spot them.

Protect your privacy

Your privacy is important. If you think someone is watching, listening to, or tracking you, you should consider getting some counter-surveillance equipment . . . but you should also probably contact the police. Counter surveillance is a good way to prove someone is monitoring you, but if you’re afraid for your safety, let the police get to work figuring out who’s spying on you and how they’re doing it.

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