The omnipresence of CCTV and its impact on privacy has led one researcher to propose an opt-in facial blurring system for people uncomfortable under the gaze of electronic surveillance systems.

According to New Scientist, [1] Hewlett-Packard computer scientist Jack Brassil [2] and his team have created "Cloak," [3] a technology designed to protect individuals' privacy when CCTV operators share images. If fielded, the system's participants would be akin to those on the national "do-not-call" list, which targets unwanted telephone solicitation, Brassil says.

To opt into Cloak, a person would first need a "privacy enabling device" - most conveniently a mobile phone with GPS capability. The device would wirelessly beam the user's position, direction, and velocity to a central system server. 

Participating CCTV operators, such as government agencies and businesses, would sign up with Cloak and system software would then electronically obscure participating individuals' faces. In Hewlett-Packard's simulations, the technology is effective even in dense crowds.

But as Ian Brown [4], a research fellow at the Oxford Internet Institute [5] in the United Kingdom, notes, the cure may be worst than the disease. People who opt-in to Cloak could be tracked everywhere they go, in real time, through the system and their wireless devices.

Brassil, according to New Scientist, admits that Cloak may not be for everyone; nor is the technology an end in itself. What he's more interested in is promoting discussion of privacy and the need for privacy enhancing technologies in a world where surveillance is everywhere.