Photography by Axel Crettenand, Photo Editing by Martin Hertig

It seems like every week there are new smart products cropping up, boasting their ability to track your routines and adapt to your preferences, all in the name of sleek convenience. But concerns over data privacy are nipping at the smart market’s heels.

Enter Martin Hertig’s “Sensible Data,” a playfully interactive art installation designed to make us question our digital exchanges. Composed of three drawbot-style machines, the exhibit collects and then “leaks” your personal data by stamping out a profile of you on an index card. To interact with each of the three machines, all you need to do (respectively) is take a selfie, send an email, and then push a button. The machines dutifully produce a tangible record of these commonplace actions, reminding (or perhaps warning) us of the invisible hands collecting information every time we move around some bytes.

Sensible Data ECAL/Martin Hertig from ECAL on Vimeo

The user takes a selfie with an iPad, which connects to a Raspberry Pi via Dropbox. A Python script then takes the image and uses openCV to convert it to a line drawing, which is then performed by the drawing machine. In the next step of the exhibit, the user sends an email. This prompts the Pi to send your photo to Rekognition, an online facial and concept recognition service which determines your gender, age, mood, and how beautiful you are (measured as a percentage). This information is all stored in a database, and the second machine stamps it out on your profile card.

Finally, the user is asked to press a rather dubious button. It’s actually a fingerprint scanner. Once your fingerprint has been received, the third machine gives your card a stamp of validation, and you receive an email with all of the personal data of a previous user — without their knowledge.

Hertig modified the Piccolo, an open source, Arduino powered drawbot, to create the three machines. Hertig uses a Raspberry Pi to power the installation, which runs a Python script for each step of the interaction. All of the stamps and mechanical parts of the machines were laser cut.

Hertig says he was partly inspired by the multiplayer mobile game Ingress, which logs players’ locations via GPS. “There is a paradox between wanting to share and on the other hand wanting something like privacy,” he says. He had noticed that people are much more willing to provide their personal data when the trade-off is a fun experience, and wanted to bring this dynamic to his installation:

“We do not expect data to be leaked because most of us never had a bad experience. Most people only realized in the end of the process how much that they actually gave. The data collection is quite well hidden by the playful nature of the machine. People were not concerned at all during the process, it was more like an amusement park attraction. Most people, including me, don’t really know what a system is allowed to do with their data and what not. I never read any privacy policies, and usually just agree. Surveillance and data logging are very abstract topics. You don’t see what’s happening. I wanted to make this complex topic more tangible.”


As a millennial, the three actions (selfie, email, button) originally struck me as fairly inconsequential. Personally, the real power of the exhibit lies at the very end when Hertig puts the user on the receiving end of someone else’s data. The realization that your data will also be sent to a future participant begs a change in perspective — perhaps these actions aren’t so inconsequential after all.

At least this particular data collection system is gracious: The last frame of the video reads “Thank you for your contribution!”