The first full presentation of Loca: Set To Discoverable was at ISEA2006 and ZeroOne in San Jose, USA in August 2006. Proof-of-concept versions were presented at Kiasma, Helsinki (Pixelache, 2005) and at RCA, London (2005). Loca: Set To Discoverable has since been exhibited at, International Festival of Art and Mobile Media, Brazil (2007).

At its premier full presentation at ISEA2006 and ZeroOne in August 2006 the Loca art group were able to track and communicate with the residents of San Jose via their cellphone without their permission or knowledge, so long as they have a Bluetooth device set to discoverable. Deploying a cluster of interconnected, self-sufficient Bluetooth nodes within inner city urban environments, Loca observes people's movements by tracking the position of the Bluetooth enabled devices that they carry. Over 7 days more than two thousand five hundred people were detected more than half a million (500,000) times, enabling the team to build up a detailed picture of their movements. People were sent messages from a stranger with intimate knowledge of their movements. Over the course of the week the messages became gradually more sinister, the would-be friend mutating into stalker, "coffee later?" changing to "r u ignoring me?"

For participants the experience of Loca is intangible, it is to do with what is not seen. Loca aims to lightly touch large numbers of people. The aim is not complex interaction, but subtle affect, and only a minority of people will receive it, let alone give it any more than passing thought. Loca is like a picture glanced at sideways, a message caught in the corner of the eye, or a mosquito swatted on the arm. If accepted, the messages explained the nature of the project and gave directions to the Loca Stand.

Here the 'user' is passive and monitored. Another element of Loca introduces an element of participatory, urban play. Loca Stickers were introduced to make visible and tangible the traces of digital identities, taking the project off the mobile phone. Loca Stickers enable people to record the presence of a uniquely named device and become a small piece of surveillance code, acting out one function of the Loca network.

The nodes were encased in concrere and fixed to street lights in the park, at pedestrian crossings on road intersections, and buried in the earth by a popular bar terrace. Others were deployed in hotels, cafes, and popular destinations such as cinemas. hey were hidden in flower pots, underneath a chaise longue, and in the foot of the podium used by the cinema ticket collector. The process of presenting the project turned into a performance in its own right, with the Loca team constantly visible about the city centre in bright orange workman overalls, climbing ladders, in and out of hotels, deploying and maintaining the network.

In the first project of its kind, some higher level interactivity attempted was found to be beyond the platform. None the less the system was fully operational during the full length of the exhibition, during which more than half a million data points were recorded.

On the final day of ZeroOne a node left in the downtown Sainte Claire Hotel was taken away by San Jose Police Department as a suspicious object and "booked in evidence". This took place on the same weekend in August 2006 that 3 Palestinian-Americans were arrested for possession of 1000 cellphones, which the authorities suspected were to be used for surveillance or as bomb detonators. Technology is often imprinted with our hopes and fears, and it says a lot about contemporary America that the SJPD chanced upon Loca's genuine DIY surveillance, but it was the people with Arabic names who were detained. The police revised the status of the node from "Evidence" to "Found Property" and the artists were able to retrieve it, complete with a log of data on people's movements at the police station, whether they be officers, criminals or simply people passing by.