At the Computers, Privacy & Data Protection (CPDP 2012) conference I learned about a new concept: participatory sensing, also known as participatory surveillance.
The idea is to allow owners of individual sensors to connect them together to create a network of sensors that can be used to monitor the condition of a certain area. An example is the use of small air pollution sensors to measure the air pollution in a city (the AirQualityEgg project). Another example is to enable access to CCTV camera footage from private buildings (hotels, apartment buildings) by emergency services in the case of earthquakes (ASPIS). Depending on the type of sensor, there is an inherent privacy problem when a sensor in a private space can be accessed from outside. This is particularly the case in the second example above, when the camera involved is in a bedroom for example. An intriguing solution to this problem is to add a motion sensor to the camera that can detect earthquakes, and that only switches on the camera if the detects an earthquake.
Ultimately, the idea is to use smart phones (that have several types of sensors, quite a bit of computational power and have a mobile network connection) as an ad-hoc sensing network (SEEMOO). I believe these concepts are an excellent area of research to apply the techniques from our Revocable Privacy project on order to limit the privacy problems.
Side note: as was put forward during the discussion, surveillance is the wrong word in this context. If data snooping by the FBI as well as collecting air pollution data are called surveillance, we need a different word for the latter. Any suggestions are more than welcome.