You might not know, and that’s exactly the problem. Software that does this, often called stalkerware, is designed specifically to run invisibly, with no icon, no notification, nothing that gives it away while it’s active.
What stalkerware actually is
Stalkerware is commercially available software that can be installed on a phone, usually by someone who has had physical access to it, and once it’s there, it can track live location, read messages, see browsing history, and in some cases record audio or video, all without the phone’s owner knowing.
Research published in 2024 found the UK to be the third most affected country in Europe for stalkerware, with tens of thousands of mobile users affected across Europe in a single year. The same research found that most people, women in particular, significantly underestimate what this kind of software is actually capable of once installed.
Signs worth paying attention to
There’s no single definitive sign, but a pattern worth noticing is someone consistently knowing things they shouldn’t be able to know. Turning up somewhere you didn’t tell them you’d be. Referencing a conversation you had with someone else that they weren’t part of. Knowing you’d left the house, or arrived somewhere, without you telling them.
None of these on their own proves stalkerware is involved, but a consistent pattern of knowing things they have no ordinary way of knowing is worth taking seriously.
What the law offers here
Beyond the general offence of controlling or coercive behaviour, there are legal routes built more specifically around stalking and surveillance:
Stalking is a specific offence under sections 2A and 4A of the Protection from Harassment Act 1997, inserted by the Protection of Freedoms Act 2012.
The Stalking Protection Act 2019 created a civil Stalking Protection Order, which is genuinely useful to know about because it can be applied for even before any criminal charge or conviction. It can require someone to do specific things, including surrendering devices, to reduce risk to the person being targeted.
If you think this might be happening to you
Checking a device for stalkerware safely matters, doing it the wrong way can alert whoever installed it that you’ve noticed. If you’re in this position, it’s worth getting proper guidance on how to check safely before doing anything on the device itself.
Keeping a written record of the specific things they seemed to know, and when, can matter later even before you’re sure what’s causing it.
Our second guide, Keep A Record, covers how to document this kind of pattern safely if you’re not ready to act on it yet, or aren’t sure what you’re dealing with.