In the heart of the Brazilian Amazon, armed men wearing balaclavas and wielding firearms intimidated me and two other journalists on a remote riverbank near the Colombian border in February. We had ventured into the rainforest to investigate the surge in violence and illegal mininganddrugtraffickingthatthe Amazon has witnessed since 2016, and to map the presence of cross-border armed groups. We are part of Amazon Underworld, a media alliance comprising more than 30 professionals. We knew that the region harboured shotgun-carrying gold miners whoillegallydredgethe river with gargantuan barges, and Colombian guerrillas who cross into Brazil to shake the miners down forgold. But the armed individuals who stopped us were affiliated with the state - a rogue military police unit that oversees and shields illegal mining operations. Working outside the law, they amass millionsof dollars in gold payments annually. There, in their shadowy domain, no one who asks questions is welcome. The leader of the armed outfit demanded that we delete all the photos we had taken during two days of observing mining barges, before seizing our memory cards. Fortunately, we had a hidden backup.