From military-grade drones to sensor systems and experimental technology, the EU and its members have spent hundreds of millions of euros over the past decade on technologies to track down and keep at bay the refugees on its borders. Poland's border with Belarus is becoming the latest frontline for this technology, with the country approving last month a €350m (£300m) wall with advanced cameras and motion sensors. The Guardian has mapped out the result of the EU's investment: a digital wall on the harsh sea, forest and mountain frontiers, and a technological playground for military and tech companies repurposing products for new markets. The EU is central to the push towards using technology on its borders, whether it has been bought by the EU's border force, Frontex, or financed for member states through EU sources, such as its internal security fund or Horizon 2020, a project to drive innovation. In 2018, the EU predicted that the European security market would grow to €128bn (£108bn) by 2020.