Wearable computing devices are heading for the mainstream but unless issues around privacy are tackled now, those problems are only going to get bigger as the devices themselves get smaller and less noticeable.
Wearable tech, from activity trackers through to Google Glass and the much-rumoured Apple iWatch, is part of a new category of devices that allows users to measure and record their own behaviour and the world around them.
But just as wearable computing comes in a number of form factors, so too do the potential privacy issues it creates — some a way off, some more immediate.
As a result, policy makers to be discussing the implications of wearable technology now, while it's still at an early enough stage of adoption, according to Chris Brauer, director of the Centre for Creative and Social Technologies at Goldsmiths University, who has conducted a study of wearable computing.
"We are often reactive in this process," he said. However, as the next generation of wearable devices become less obtrusive, the privacy problems could get worse, not better.
"The Google Glass conversation is about people with the glasses on and the camera is highly visible, but as these devices get embedded into textiles and have much smaller cameras and much less visible applications of the technology, it's going to create a whole raft of emergent issues.
"That's going to come swiftly in the next 18 months and introduce a different conversation which is less about the issues right now regarding privacy and more about what are we going to do about this as it embeds into all aspects of our everyday lives."
His research shows a certain amount of ambivalence towards such devices: while two-thirds of users of such devices said their wearable tech had made them fitter, a similar percentage of the general public thought such devices should be regulated in some way — and one in five of those queried thought they should be banned.
Bauer said early adopters of activity tracking devices believed they were "investing in themselves" when using such tech, and saw a benefit in sharing the information it gathered. "They use these devices to track and develop data for their quantified self, and they are exchanging that data for improvements in their life," Bauer said. "If they get benefits in return from exposing personal data, then they would be willing to do it."
Indeed, according to Bauer's research, sponsored by cloud computing company Rackspace, one in three respondents would be willing to use a wearable health and fitness monitor that shares personal data with the NHS or a healthcare provider.
But Bauer said there was a potentially "troubling" downside to such a move: if, for example, insurers began to expect access to such data, then those unwilling to live their lives "healthily" could see their insurance premiums increased. Similarly, "unhealthy" people might choose not to use the tech at all, rather than risk being penalised by healthcare institutions for doing so. "If it's not good, releasing that individual data will put you at significant risk and that will lead to two-tier usage patterns [of the technology]", he said.
Whereas activity trackers may lead to concerns about how our own data could be used, something like Google Glass raises concerns about the privacy of others.
In some respects, Google Glass has become a lightning rod for these concerns, partly because it's the most high profile device and also because it records information about the world around the wearer, rather than just about the wearer themselves. For example, earlier this week Google confirmed that it would not currently approve any facial recognition apps for Google Glass, and said it would only do so in future if it had "strong privacy protections in place".
Over the next couple of years, wearable devices are likely to become more integrated with each other too. Bauer said one likely next step was applications to combine all the different types of data gathered by individual devices — your Glass data could be mashed up with the information gathered by your FitBit, for example.
"While something might track concentration and another thing sleep patterns and another your mood, the triangulation of those things will provide a much richer fit and more utility than those things in isolation."
With such integration on the horizon, wearable tech is opening up even more ways for the data it collects about individuals to be used — or misused.