Despite their ubiquity and relevance, data collection practices remain opaque and their carbon footprint has rarely been investigated. What is more, data collection is a key resource in the global supply chain of AdTech, the primary business model of the data economy system. The Carbolytics project, developed by artist and researcher Joana Moll in collaboration with researchers from the Barcelona Supercomputing Centre, is a way of understanding the collective existence of cookies and their role in the outsourced production of carbon dioxide. The interactive web-based installation shows the average global volume of cookie traffic in real time and demonstrates how cookies parasitize user devices to extract not only personal data but also energy. Or, in the words of Matthew Fuller: in digital capitalism, the myth of the invisible hand of the market has been replaced by the reality of the partially visible cookie.