Cameras are popping up everywhere across Rotterdam: mounted on buildings, built into doorbells, towering over streets and squares. But how many are there, exactly? What do they record? And is it still possible to move through Rotterdam unobserved? Armed with an app and a good pair of walking shoes, researchers are taking to the streets to find out. Anyone can join them.
The help of residents is very much needed, says researcher Arthur De Jaeger, because building a complete register of all cameras in Rotterdam is a huge undertaking. Surveillance technology has spread through the city like wildfire in recent years.
'It is very difficult to give a precise estimate of the number of cameras in public space', says De Jaeger. 'The number of smart doorbells alone, for example, is estimated to be between 1.5 and 2 million in the Netherlands.'
Still, the researchers are determined to map how many cameras Rotterdam has, what they record, what type they are and who installed them. 'We are doing this because we currently have no overview, but also because we want to question the taken-for-granted presence of cameras in public space.'
Mostly privately owned
One of the big questions: what does it mean when public life increasingly takes place under the eye of a camera? 'Cameras influence the way I move through the city', says Louisa Teichmann, who is involved in the project as a citizen researcher. 'I don’t want to look suspicious or draw attention.'
Teichmann used to associate camera surveillance mainly with the police and government, she says. But during the research, she noticed that most of the cameras she came across were privately owned. 'That was interesting to me.'
Do cameras really make the city safer?
Of the tens of thousands of cameras in Rotterdam’s public space, only a small share belong to the municipality. The vast majority have been installed by residents and businesses. Often, they are intended to increase safety. When intruders come knocking, at least there is a camera system ready to register it all.
But it’s far from clear whether all those cameras actually make the city safer. Meanwhile, they record not only potential burglars, thieves or vandals, but everyone moving through the city. Anyone taking a short walk through Rotterdam’s city center is filmed hundreds of times. How desirable is that? 'The presence of cameras has become so normalised that the debate about them is largely absent', says De Jaeger.
Spotting cameras for science
The researchers are trying to spark that conversation in different ways. They worked with Belgian artist Maarten Inghels, known for his Invisible Routes, to find out whether it is possible to walk through Rotterdam unseen. It took many attempts, but eventually a camera-free route was found.
Anyone can contribute to the research. With a specially developed app, CameraSpotter, users can easily add cameras to the digital map. 'You can go out on your own, but we also regularly organise data walks, where we search for cameras together', says De Jaeger. 'In this way, we will be building Rotterdam’s first public camera register together over the coming months.'
About the project
Start Making Sense is a project by the Leiden-Delft-Erasmus Centre for BOLD Cities, in collaboration with the Resilient Delta initiative. Together with Rotterdam residents, researchers are mapping cameras in public space. People can take part through the CameraSpotter app, data walks, workshops, teaching or research activities. On 14 September 2026, the debate evening Big 010 is watching you will take place at ARMINIUS, preceded by a camera-spotting tour around the Arminius church.
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Questions?
For more information, contact project coordinator Arthur De Jaeger.This article is part of SCIENCE & THE CITY, a series of stories and videos about citizen science. In this mini-series, we speak with researchers and Rotterdam residents who are working together to investigate questions that matter to the city.
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