Metro Bank experienced the first “bank run” in the social media era. Here’s why it matters.

Just last week, UK-based Metro Bank experienced the first social media era bank run, spiraling from false rumors spread through Twitter. The bank ultimately closed on the market down 11%, an all-time low. The bank has been briefing staff on how to reassure customers that their money and safety deposit boxes are safe after a flurry of WhatsApp messages caused queues at some of its London branches over the weekend. One branch in Harrow in north-west London on Monday spilled over with 40...