In today’s digital world, every single click, every search query, every second spent on a webpage, every GPS ping and every time our device is close to another device, send a little bit of information about us out into the digital environment – what type of content we find interesting, what products we want to purchase, where we live and where we go to work, even with whom we spend time. This wealth of information is systematically collected by companies, governments and other parties for various purposes – perhaps most frequently to predict and influence human behaviour for profit.

‘They know everything about me’

Zhang’s research shows that many people develop their own “folk theories” to explain digital tracking, often in the absence of clear and transparent information. ‘People know their data is being collected, but they often don’t know how exactly,’ Zhang says. ‘So they fill in the gaps with their own interpretations – and those interpretations strongly influence how they feel online.’

Across interviews, surveys and experiments, Zhang found that most individuals believe commercial companies are the main watchers, constantly gathering information to target advertising or drive profits. ‘Many participants told us, almost word for word: “They know everything about me,”’ Zhang says.

Too accurate

The research reveals that certain data practices reliably intensify the sensation of being watched. These include the use of highly sensitive personal information, the combination of multiple types of data and personalised predictions that feel “too accurate”.

‘The moment someone sees an ad that relates directly to their sensitive data or an algorithmic profile that matches them too closely, that’s when the feeling of surveillance spikes,’ says Zhang.

No real control

Once that feeling is triggered, it has real consequences, Zhang found. People tend to react negatively not just to the ad itself, but also to the brand and the platform that delivered it. At the same time, perceived surveillance can motivate users to adjust their privacy settings – though many instead slip into privacy cynicism, resigning themselves to it happening. ‘A lot of people told us they feel they have no real control,’ Zhang says. ‘Even when they care deeply about privacy, they don’t believe they can meaningfully protect it.’

Some technologies feel more intrusive than others

Not everyone experiences the feeling of being watched to the same extent. Younger, highly educated users, those with more privacy concerns, and those who tend to believe in conspiracy theories are more likely to feel surveilled. The effect also varies across devices: social media platforms and web browsers rank among the most surveillance-evoking technologies, while smart watches and smart home devices are perceived as the least surveilling. ‘People react differently depending on both who they are and what they’re using,’ Zhang says. ‘Some technologies simply feel more intrusive than others.’

Overall, Zhang’s research highlights a growing emotional tension in the digital world. As Zhang puts it: ‘We rely on digital technologies more than ever, but at the same time we’re increasingly unsettled by how much they seem to know about us. That tension is reshaping trust, behaviour and the entire digital experience. The time is overdue for advertisers, ad platforms, and policymakers and regulators to be looking into how to shape this area for the better in the coming years.'