Every 10 minutes, Mae’s computer snaps a shot of her screen, thanks to monitoring software her employer made her install on her laptop. A figure looms large over her workday: her activity score, a percentage calculated by the arbitrary measure of how much she types and moves her mouse.

It’s hovering at about 62% when we speak. “That’s quite good. If I’m on a Zoom call that counts as 0% [activity], even though I’m in a meeting,” she explains, adding that she watches videos and attends calls regularly as part of her role.

Mae, who is in her 20s, was one of many workers who got in touch with the Guardian to share their experience of being monitored. She works remotely in marketing at a company where surveillance has become part of the job.

Employees use Hubstaff, one of the myriad monitoring tools that companies turned to as the Covid pandemic forced many to work remotely. Some, such as CleverControl and FlexiSPY offer webcam monitoring and audio recording.

Mae says she often has dry eyes and a sore head at the end of the working day. “Tracking doesn’t allow for thinking time or stepping away and coming back to work – it’s very intense.”

Although Hubstaff states that the statistics should be understood in the context of the role, and warns against unrealistic activity goals, Mae says her manager has asked her about her scores and compared them with those of other employees. “Having that conversation put it on the back of my mind – they are looking at these scores.”

Now, when she undertakes work that could drag this number down – including taking notes on paper – she pauses the tracker, meaning she sometimes ends up working overtime to hit her contracted hour count.

“I feel frustrated that I’m being marked by some automated system that reflects me as being not as good a worker as I believe I have been.”

She also finds it negatively affects her productivity, to the point where she has taken sick leave to catch up on work without being tracked. “I feel constantly watched. I’m much better at taking myself away and working quietly. It feels liberating to turn it off. There’s got to be a level of trust beyond screenshots.”

During the pandemic, there was a spike in searches relating to workplace surveillance, such as ‘how to monitor employees from home’, according to the Institute for Public Policy Research (IPPR).

A poll by the Trades Union Congress (TUC) in 2022 found that 60% of employees had experienced tracking in the last year. Henry Parkes is a senior economist at the IPPR and the author of a recent report on the rise of surveillance practices. He is calling for more transparency and says the exact scale of workplace monitoring is hard to judge without open data.

He warns that surveillance is “not only about logging”, adding: “ It’s the potential for it to be used against workers. This technology can just be used to exert power over employees in a way that wasn’t possible before.

“There’s potential for creep, where software is deployed for one purpose, [such as] checking when people are in, but there are all these other features you can use. You can start to analyse what they are doing.”

If employers rely on this data to make workplace decisions, there is a risk of algorithmic bias, Parkes says, while young, female and minority workers are more likely to be surveilled. He notes that some employers use systems that deploy aspects of AI in this process. “It is a black box, it’s not transparent – you feed data and it spits out a result. The more we rely on AI, we need to be really careful they’re not discriminating on the basis of gender or ethnicity. We could end up with decisions that are prejudiced, but appear neutral.”

And there are limitations to focusing solely on the accuracy of systems used in monitoring. The competency of technology, such as Fujitsu’s facial recognition AI model that assesses the concentration of workers, “will inevitably improve”, Parkes says, adding that “the rate they are improving at is quite scary …But it’s [still] dehumanising and not how people are able to operate all day,.”

Surveillance, which has long existed in some work environments including call centres, could become normalised in a widening array of sectors, Parkes says. “We wouldn’t accept your boss just standing behind you all day, watching and analysing everything you were doing. But basically the equivalent of that is possible through technology.”

Excessive monitoring can be counterproductive for companies too: it is associated with higher staff turnover rates, and there is evidence to suggest it can lead to resistance and counterproductive outcomes, including workarounds to improve statistics.

Parkes says: “Your metrics can get more sophisticated but there are limits if we take metrics as gospel. There are lots of different ways people can be good at jobs – an excessive focus on data could be a problem. That’s not to say that there isn’t a role for data, but it’s about how we use it in making decisions. We want to be judged on outputs.”

Carlos*, who is in his 40s and works in customer service at a high street bank in London, knows how challenging this can be. Post-pandemic, his job is hybrid and he says he is tracked relentlessly when working remotely. “Our ‘performance’ is counted by the minute. I have found myself having to explain the reasons for a longer toilet break.” He says the intensity of the monitoring has affected his wellbeing.

Carlos says that in appraisals, he is told by how much he has deviated from the ‘optimum’ time spent dealing with each customer query. But he isn’t told how this score is calculated. “That’s what makes the job really stressful – it’s not transparent,” he says.

Some workers are pushing back on workplace surveillance through unions. Adam*, who is in his 50s and works in social housing for a local authority in the south of England, says management has begun using vehicle tracking intrusively in recent years.

“We are routinely tracked – rang if we’re taking too long, or if our manager thinks we are not in the right place. It’s not unusual for council vehicles to have trackers, but it’s unusual for them to be used in any other way other than if a driver has an emergency.”

Adam says surveillance has been increasingly used “to catch people out”. “It makes you fearful. You always worry about being watched – sometimes we might be having a cup of coffee for half an hour. It adds pressure to an already stressful job. It’s not paranoia when they are out to get you.

“What the council is doing is using trackers to keep surveillance on us. Simply ringing people up to ask about why they’re taking a specific route, when we have no [set] routes … It’s bordering on harassment.”

His supervisor appears to have backed off since he reported it to the union. “I bit back. They are now aware that the watchers are being watched.”

* Names have been changed.