The Critical Engineering Working Group Julian Oliver
Danja Vasiliev

PRISM: The Beacon Frame.
Speculative NSA Forensics Equipment.

PRISM: The Beacon Frame is a speculative, functional response to the general absence of information as to what NSA PRISM equipment actually looks like. Centered with the image of the prism, the project seeks to provide public direct contact with the aesthetics, technology and strategies used by states against their publics (and others), retained from critical contact by an opaque and coveted surveillance culture.

The project was initially developed in two days by Julian Oliver and Danja Vasiliev as part of ArtHackDay Berlin, September 2013. It was further developed for the Transmediale 2014 main exhibition, featuring selected works from ArtHackDay. On the opening night of Transmediale, PRISM: The Beacon Frame successfully hijacked the cellular connection of at least 740 phones, without any interaction from users.


This iteration of the project is a field deployable wireless surveillance and GSM interception unit comprising a robust tripod, large glass prism, nano computer, nano projector, GSM antenna and cellular communications base-station (also with computer).

It employs the same techniques of wireless (WiFi) device localisation and mapping, cell-tower hijacking and wireless packet inspection known to be in use by state sanctioned surveillance agencies such as the GCHQ (UK) and NSA (USA).

When activated, the computer scans for local cell towers owned by mobile service providers (Vodafone, o2, AT&T and so on), building a list of their unique properties. The prism then begins rotating and one by one each cell provider is impersonated by the PRISM tower. Activated mobile phones in the presence of the tower will hop onto the rogue network, 'recognising' its properties and believing it to be trustworthy.

At that point they are each sent SMSs of a troubling, humorous and/or sardonic nature. Data corresponding to these events are projected through the prism, in turn showered onto the walls in a rich and exploitative light show.

Audiences peering into the prism 'see inside' the internal workings of this intervention, from the unique ID of the phone intercepted to messages sent.

Projected onto a wall behind the tower structure is a data-rich, dynamic 2 dimensional map of all WiFi enabled devices in the vicinity of the installation. Typically comprising smart-phones, the location, unique 'hardware fingerprint' and hostname ("Tara's iPhone") are plotted on this map, updated with every movement by the owner of that device. Audiences in room with the Tower may note their friends approaching, merely by recognising their name on the map.


During the opening night of Transmediale 2014, PRISM: Tower interacted with over 740 phones. Each device was sent a notification message. Soon after, most of these devices were sent one of several different SMS, ranging in paranoia-inducing and or humorous intensity.

Whilst the intervention was met with much praise (including that of two German politicians present at the event who no doubt found it a timely comment on US interception of cellular communications from the German Parliament, right next door), a few people found the intervention too distressing to accommodate.

Complaints were made to the technical contractor responsible for the AV and networking set up of the festival. He promptly and without any due process removed the components of the installation he knew to be responsible for the intervention, effectively disabling a vital component of the work and threatened to call the German Federal Police on further complaints if the piece were to be restored.


A meeting was held between the developers, technical head and festival director. The festival director pointed out that the festival and its umbrella organisation could not afford to give the artists legal protection from a possible report to the police. Given the lack of cover and severity of the potential charges in Germany (including heavy fines and jail time), the artists chose not to restore the work.

The developers of the work Julian Oliver and Danja Vasiliev published the following statement.

We, the creators of "PRISM: The Beacon Frame", wish to express our disappointment at the disabling of a crucial element of this work at Transmediale 2014, with the threat of reporting us to the German Federal Police.

As such we've agreed that it is not in our interests to maintain the work in its original form.

It was our intention to provide an opportunity for public to critically engage precisely the same methods of cellular communications interception used by certain governments against their own people and people in sovereign states. It was not, in any way, our intention to harm anyone and nor did we.

We note that the German Parliament, right next door, has suffered directly by way of such violations.

It is vital that technology-based art remain a frame with which we can develop critical discourses about the world we live in, from the engineered to the cultural and political. Sometimes that requires that we are not limited by exaggerated fears and legal definition, but that we act proportionally and with conscience in our efforts to understand the power struggles and tensions in our (technically mediated) environment.

Sometimes this means taking risks, risks without intention to harm but to engender wider critical insights.

We wish to thank the Festival Director and the Curatorial Team from ArtHackDay and LEAP for representing us to the best of their ability.

"The Critical Engineer considers the exploit to be the most desirable form of exposure."

- Julian Oliver, Danja Vasiliev

This statement was also displayed in the exhibition space replacing the output of disabled work.

Olof Mathe, ArtHackDay instigator and co-curator of the event, wrote the following in response to the takedown:

Why the partial dismantling of "PRISM: The Beacon Frame" is unnerving.

Danja Vasiliev and Julian Oliver's work "PRISM: The Beacon Frame", made and shown during Art Hack Day Berlin, was partially taken down on Friday Jan 31, 2014 after threats of reporting to the German Federal Police.

“PRISM: The Beacon Frame” is as visually stunning as it is technically audacious. It uses wireless interception to project device information through a prism onto the surrounding walls resulting in an impressive and ominous lightshow. People close to the installation receive eerie yet playful text messages. It raises questions around our exploitative relationship to critical infrastructure. As such, it was universally acclaimed by visitors to the exhibition.

In a certain light, it's ironic that a component of the installation be taken down since it merely re-articulates some of the core questions raised by the piece: Who controls our infrastructure? Why is certain technology the prerogative of those in power? How can we foster public debate around the ramifications of technological choices?

The threat of reporting to the police is equally ironic and sad. It's ironic because the work highlights the violations the German Parliament, next door to the exhibition hall and the epitome of power, has been exposed to. It's sad because the type of pseudo-"citizen's arrest" Danja and Julian were victims of is the hallmark of the faceless bureaucracy and tacit obedience on which many power structures rely. Furthermore, the threat brings back unpleasant memories of absurdly draconian penalties for 'computer'-related crimes, as was the case with Jeremy Hammond and the late Aaron Schwartz.

How can we encourage critical inquiry into our technologically mediated environment if not through works like “PRISM: The Beacon Frame”? Art Hack Day was initiated with the express purpose of providing a haven for hackers whose medium is art and artists whose medium is tech to express themselves to their fullest ability, much like Julian and Danja advocate in their Critical Engineering manifesto. The partial dismantling of “PRISM: The Beacon Frame” is therefore unnerving. It shows how much work remains before we can genuinely begin to examine the technological underpinnings of power, society and culture.

- Olof Mathé, one of many Art Hack Day organizers



The takedown inspired a large response from the press, some of which is archived here:


The initial version of PRISM: The Beacon Frame comprised as a military-grade case contains a tiny computer (running GNU/Linux), nano projector, wireless network adaptor and large solid-glass prism. When activated, the prism begins rotating while the embedded computer listens for connection requests from devices made to local wireless access points. When detected, the hostname and unique hardware fingerprint of the device is projected through the prism and onto the surrounding environment; a subversive and exploitative light show.


5 Feb 2014,