During the past years 5G has been adverstised by industry leaders as the future of the tech. Nevertheless there is little data about its environmental impacts and about the necessity of such infrastructure for future challenges (global warming, resource scarcity, …). This talk intends to describe the 5G infrastructure and some of the different controversies around it like energy and environmental impacts. The rise of big tech infrastructure, such as 5G, without any public consultation is heavely problematic as it locks down on a specific, and presumably unsustainable, technological path. 5G is likely to be a keystone to reclaim governance and democratic debate on future infrastructures. 5G also asks a key question : can we collectively steer and manage the evolution of internet traffic or are you condemned to an exponential growth to the benefit of some private actors ?