Yesterday Ubisoft, the publisher of the upcoming Watch Dogs, introduced a new website named “WeareData.” The website shows all of the public data available in the cities of Paris, Berlin, and London in an interactive map. The data used for the website includes social media posts (Foursquare, Twitter, etc.), traffic lights, mobile phone networks, and running subway trains.

The purpose of the website was to point out how much public data there already is, and how interconnected it is. The effect is fascinating and relatively creepy, which keeps with Ubisoft’s marketing strategy for Watch Dogs. The conceit for Watch Dogs is that the player is a hacker in a Grand Theft Auto-style open city, with the added ability to hack city systems, cameras, and the smartphones of pedestrians.

Today Ubisoft has released a video showing just how the data seen on WeareData was obtained. It turns out access to the data is surprisingly simple, though development of the visualization map itself was a bit more difficult.