The possibility that data could be inadvertently exposed in a misconfigured or otherwise unsecured database is a longtime privacy nightmare that has been difficult to fully address. But the new discovery of a massive trove of 184 million records—including Apple, Facebook, and Google logins and credentials for accounts connected to multiple governments—underscores the risks of recklessly compiling sensitive information in a repository that could become a single point of failure.In early May, long...