By now, it’s common knowledge that if you have a device—whether a fridge or a smart TV—it’s collecting information about you and sending them back home. It’s not controversial anymore.
You can opt out of this in most cases, but how do you know if a device has actually stopped snooping on your activities? How can you tell when a device that isn’t officially meant to collect and share data is doing it anyway? It’s not always easy or 100% reliable, but there are signs to look out for.
Your tech is watching more than you think
The companies that make our smart gadgets use all sorts of euphemisms for digital surveillance to make it more likely you’ll click “I agree” when reading the privacy agreement. That’s if you bother to read it at all. This is why it was possible for TV makers to use technologies like ACR or Automatic Content Recognition to blatantly snoop on all your TV activity, without people realizing that they’d really agreed to. Even worse, it’s an opt-out system, which means unless you say “no” the answer is taken as “yes”.
Credit: Cianna Garrison / How-To Geek
The telemetry and analytics can include app usage, viewing habits, voice snippets, location, and detailed metadata about other devices on your network. The signs that a device might be doing this are usually subtle, but that’s not the same as being invisible.
The subtle signs of silent surveillance
Often, detecting spying is more about noticing a weird pattern over the course of days, weeks, or months, rather than a single dramatic smoking gun. Some general things to look out for include:
- A battery-powered device suddenly drains its battery quickly and becomes unusually warm even when you weren’t doing anything on it.
- Network activity spikes leaving your home network from devices that have no need to communicate significantly outside your LAN.
- Advertising that seems to specifically reflect interactions you’ve had with a device that you haven’t agreed to any data sharing for.
- Permissions change after an update or after a period of time. Some manufacturers are sneaky and use updates or policy updates to reset your privacy options, or subtly get you to agree to resetting them without really knowing that you’re doing it.
- Your router or ONT’s outbound traffic lights are flashing when you don’t expect them to and have no explanation for it.
Now, none of these are definite, but they can be a tip-off that you should do a closer investigation about what data is leaving your home network.
The usual suspects: Gadgets that love to listen
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While any device with an internet connection is a potential snitch, some are more likely culprits based on how they work, what permissions they ask for, or simply a reputation for questionable privacy practices from obscure brands.
- Smart speakers and other devices with voice assistants that activate with a “wake word” are always listening and recording. Which means they have the potential to “accidentally” send that recorded voice data to a server somewhere.
- Smart TVs, which as I mentioned commonly have technologies like ACR activated by default these days.
- Smart cameras and doorbells are notorious for this. Especially if it’s a cheap model from an unknown brand, or even a counterfeit device.
- Mobile or smart TV apps that ask for overbroad permissions that have nothing to do with their core functions.
These are just the most likely in my opinion, but you should treat any networked device as a potential threat.
How to catch your devices in the act
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You don’t have to be a network security expert to figure out that a device is doing something fishy—I’m certainly not.
These days you can use a tool like Wireshark to do a sophisticated analysis of your local network traffic, but the truth is that many modern routers have apps or interfaces that give you all the basic tools you need.
For example, my TP-Link Deco mesh router system shows my information about individual devices, and even lets me change their individual network permissions to ensure they don’t get to send any data somewhere I don’t like.
If you have a modern router system like this, you can find the devices you suspect on its client list, and then look at the data on its traffic. Is it sending large amounts of data at frequent intervals? Is that expected behavior? Watch for frequent outbound connections, big uploads, or connections to any unfamiliar domains.
You can usually block all outbound traffic for a specific device on your router’s dashboard. Devices like smart TVs will obviously stop working if you do this, but a local IP camera that you only monitor from within your LAN or a smart light bulb has no reason to communicate with the outside world.
You should review all your app permissions and remove permissions from apps that don’t need them. Delete any apps you don’t use anymore. You may need to do this again after a big OS update.
Check the menus of your smart devices for labels like “diagnostic”, “telemetry”, “improved product experience” and the like. Disable it all.
Locking down your digital life
If you think a device might be sending out data you don’t want it to, you have a few options. For example, you can put your IoT devices on their own isolated network. There are various ways to do this, but many modern routers let you create a virtual network for a subset of devices. Change the default username and password on devices that can be logged into remotely just to be safe.
If the device you’re concerned about is from a well-known brand, you may want to look up the specific privacy measures people have taken, or if there’s any evidence for actual privacy issues with that device. If you have devices from uncertain origins, it’s honestly better to just disconnect them and replace them with something that’s a devil we know.

