A huge new screen installed in London's iconic Picadilly Circus will track cars and people who pass by to display targeted ads. As first spotted by Wired, the 790 square meter screen can produce 281 trillion different colors from 11 million pixels spaced 8 millimeters apart. It will be the largest display of its type — about the size of four tennis courts — in Europe when it’s switched on later this month. Landsec, the company that owns the screen, says it features recognition technology that’s influenced by the people and things around it, allowing ads to better target local viewers.

Landsec says hidden cameras will analyze the make, model, and color of cars that drive by as well as the age, gender, and even the feelings of nearby pedestrians in order to customize ads for the local audience. The technology can be used to program certain ads to play when specific cars drives past, for example, or in response to weather changes, or news and sport reports. The new screen will also provide complimentary Wi-Fi for people in the surrounding area.

In an email to The Verge, a spokesperson for Landsec said the screen can react to these external factors, but would do so without collecting or storing any personal details. “For example, the branded content displayed on the screen could change depending on the color of vehicles,” she said. How the technology is used depends on the approach chosen by the brands.

This giant spying screen will replace six separate ones that used to each represent a different brand. Every ten minutes, one ad will fill the entire screen for 30 seconds — the first brands to debut will include Samsung, Coca-Cola, Hyundai, and L'Oreal.

For the majority of the time though, the screen will be split up into the traditional six sections that will stream live video, sports results, and feeds from various social media platforms. As such, Landsec said it hopes that brands will be able to create content people will be able to react to, say through tweets or Facebook posts.

Landsec hasn't specified an exact date for when the screen will be turned on because it doesn’t want to cause overcrowding in the already busy traffic junction and tourist destination.