Every few weeks a list does the rounds: nine gadgets that make you impossible to track. The comments underneath are always the same, dozens of people asking “where do I buy these?” and nobody answering. So here's the honest version. Some of these things cost a couple of pounds and do exactly what they claim. Some are solving a problem you don't have. And a few of the settings already on your phone do more than any of them.
The short answer
- Worth it: a Faraday pouch for car keys, a webcam cover, a USB data blocker or charge-only cable, and a privacy screen if you work on trains.
- Only if it bothers you: RFID card sleeves, a Faraday bag for your phone.
- Skip: microphone jammers, hidden camera detectors, anti-facial-recognition glasses.
The reasoning, item by item, is below. Everything we recommend is on our everyday kit page with links, and we don't sell any of it.
1. USB data blockers and charge-only cables
A USB cable carries power on some pins and data on others. A data blocker is a small dongle that passes the power through and simply leaves the data pins unconnected, so a charging point in an airport, train or hotel lobby can charge your phone and nothing else. A charge-only cable does the same, with one less thing to lose.
What it does: removes any possibility of a dodgy charging point talking to your phone. What it doesn't do: anything at all about apps, accounts, adverts or tracking. It's for one narrow risk.
Your phone already guards that risk itself. Apple's own guidance is that “by default, you need to first unlock your iPhone or iPad to connect to an accessory or computer”, and that your device “will charge as usual when connected to a USB power adapter, even if you don't unlock it”. On Android, plugging into a computer gives you a “Charging this device via USB” notification, and nothing transfers until you tap it and choose File transfer yourself.
So why bother? Because in August 2025, researchers from Graz University of Technology presented work at the USENIX Security Symposium showing that this asking can be bypassed. Their ChoiceJacking attack used a cheap malicious charger to fake the user's own tap and turn the data connection on by itself. It reached personal files on devices from eight vendors, including the top six by market share, and on two of them it worked on a locked phone. The researchers reported it, and say all but one vendor, including Google, Samsung, Xiaomi and Apple, acknowledged the problem and are adding fixes.
That's the honest case for a data blocker: your phone's protection is good, it has been broken once, and a fix that can't be bypassed by software costs less than a sandwich. If you have a GrapheneOS phone you're already covered anyway. GrapheneOS adds its own USB-C port control, set to charging-only while the phone is locked by default, and it disables the data lines at the hardware level rather than trusting the operating system to say no.
2. Webcam covers
A sliding plastic cover for a laptop camera is the cheapest certainty on this page: if the lens is covered, nothing is filming you. A piece of tape does the same job for nothing.
Two honest caveats. It does nothing about the microphone, which is the part worth worrying about more. And your devices already tell you when the camera is live: on an iPhone, Apple says a green indicator means the camera is in use and an orange one means the microphone is, from iOS 14 onwards. Android 12 and later show a green indicator in the corner of the screen, and let you switch camera and microphone access off for every app from the Quick Settings panel, after which apps get a blank picture and silent audio.
So: cover the laptop camera because it costs pennies, but don't imagine it's the main event. Keeping the machine updated matters more, which is the point of our guide to which antivirus you actually need.
3. Privacy screen protectors
These are a filter that darkens the screen when it's viewed from an angle, so the person in the next seat can't read your messages. The trade-off is real and worth knowing: the screen is dimmer for you too, and you need the one made for your exact model.
Worth it if you work on trains or in open-plan offices, or if you handle anything confidential in public. Pointless at home. It does nothing to stop tracking, it stops shoulder-surfing, which is a different thing.
4. Faraday pouches
A Faraday pouch is a lined bag that blocks radio signals getting in or out. There are two quite different uses.
For car keys: buy one today. Keyless cars are constantly listening for the fob, and thieves relay the signal from your hallway to the car. A pouch by the front door ends that, and the cheap ones test as well as the expensive ones. The full story is in our guide to keyless car theft.
For your phone: only for specific moments. Sealed in a pouch, a phone can't be reached by mobile signal, Wi-Fi, Bluetooth or GPS, so it records no location and receives nothing. That's useful for a meeting you want left alone, or a switched-off evening. What it does not do is delete anything, undo what apps already collected, or help the moment the phone comes out again. Test any pouch by sealing your phone in and ringing it. If it rings, it isn't working.
5. RFID wallets and card sleeves
This is the one the gadget lists always oversell. The claim is that a thief brushes past with a hidden reader and takes money off your contactless card.
The figures are worth a look. UK Finance reported in June 2026 that contactless fraud losses across 2025 were £46.8 million, up eight per cent, out of £703.4 million of unauthorised payment fraud. So contactless is a small share of the total, and those losses cover every way a contactless card gets misused, most obviously a real card that has been lost or stolen. On the reader-in-a-crowd version, Which? says skimming has been demonstrated in laboratory settings but is “a relatively impractical way for scammers to obtain your card details”, and reports that UK Finance told it in February 2026 that there have been no recorded cases of criminals walking into a public place with a contactless reader and taking money.
Our take: a couple of pounds for sleeves is fine if it stops you worrying, and cheap sleeves work as well as a designer wallet. Just don't buy the story that goes with them. Checking your statements and turning on card notifications in your banking app protects you far more, because that's how the fraud that actually happens gets caught.
6. Hardware kill switches
A kill switch is a physical switch that cuts power to the camera, microphone or wireless radios, so no software can turn them back on. It is the strongest version of everything above, and the catch is availability: mainstream phones don't have them. The best known exception is Purism's Librem 5, which has three switches for Wi-Fi, mobile and the microphone and cameras, with all three together also cutting GPS. It's a niche phone with real trade-offs on apps and cameras, and we wouldn't point most people at it.
For everyone else, the practical version is a laptop with a built-in camera shutter, plus the software equivalents: Android's camera and microphone toggles, or on a de-Googled Pixel, GrapheneOS permissions that let you deny an app the network or the sensors entirely. Our which Pixel guide covers what a de-Googled phone does and doesn't change.
7. The gimmick shelf
These are the ones that make the lists exciting and your wallet lighter.
Microphone jammers
Small gadgets that emit ultrasonic noise to spoil any nearby recording. We have not seen independent testing showing they reliably stop a modern phone recording a conversation, and they do nothing about anything else on the device. For almost everyone this is a solution looking for a problem.
Separately, and importantly: radio jammers are illegal to use in the UK. Under section 68 of the Wireless Telegraphy Act 2006 it is an offence to use apparatus for the purpose of interfering with wireless telegraphy, and on conviction on indictment that carries up to two years in prison, a fine, or both. So the mobile signal blockers and GPS blockers that sit alongside these on the same websites are not a grey area.
Hidden camera detectors
Cheap detectors either flash a light so you can spot the reflection of a lens, or listen for wireless signals. Your phone torch and camera do the first job for nothing, and a slow look round is what actually finds cameras: smoke alarms, plug sockets and shelves facing the bed.
If holiday lets are the worry, the rules have moved in your favour. Airbnb announced on 11 March 2024 that indoor security cameras are prohibited in listings globally, “regardless of their location, purpose or prior disclosure”, with the policy taking effect from 30 April 2024. Finding one now is grounds for a complaint, not just a bad review.
Anti-facial-recognition glasses and infrared wear
Glasses and caps that shine infrared light at cameras to spoil the picture. They're aimed at particular camera types under particular conditions, we have found no independent UK testing showing they work on the cameras you actually walk past, and wearing them makes you the most memorable person on the street. Give it a miss.
The free version, which is better
If you only do the paid bits, you've spent money to fix the small stuff. The settings below cost nothing and do more.
- Turn off the permissions apps don't need.Location, camera, microphone and contacts, app by app. Our guide to cleaning up your phone walks through it.
- Use the camera and microphone toggles. Android 12 and later can switch both off for every app from Quick Settings.
- Keep everything updated. The ChoiceJacking fixes arrive as updates, not as gadgets.
- Get your details off the broker lists. Far more is known about you from data that was sold than from anything a gadget can block. See data broker removal.
- Sort the router. One evening, no new kit: secure your home Wi-Fi.
What we'd spend, in order
- Faraday pouch for the car keys, if your car is keyless.
- A webcam cover, or a bit of tape.
- A USB data blocker or charge-only cable for travelling.
- A privacy screen, if you work in public.
- Nothing else on the list.
That's the lot, and it comes to less than one of the gadget-shop bundles. The rest of the protection is settings, updates and habits, all free.