As computing hardware becomes increasingly small and ubiquitous, one thing is for certain – technology will be watching us more than ever in years to come. Which isn’t a pretty picture for privacy – we may have to simply accept that our digital footprints will be registered whenever we are out in public. But perhaps in certain situations we will be able to fight fire with fire, and use ‘virtual walls’ to protect our secrets and confidences in a world where the real walls are what’s doing the watching.