Ten years ago, Eliot Higgins could eat room service meals at a hotel without fear of being poisoned. He hadn’t yet been declared a foreign agent by Russia; in fact, he wasn’t even a blip on the radar of security agencies in that country or anywhere else. He was just a British guy with an unfulfilling admin job who’d been blogging under the pen name Brown Moses—after a Frank Zappa song—and was in the process of turning his blog into a full-fledged website. He was an open source intelligence analy...