American regulators have put mergers that they approved years ago at the heart of antitrust lawsuits—a tricky bid to curb the social-media giant’s market power. We examine the surge of an artist-led protest movement in Cuba, where dissent on any scale is a dangerous proposition. And what a cross-border, ski-slope spat reveals about European co-operation. For full access to print, digital and audio editions of The Economist, subscribe here www.economist.com/intelligenceoffer