250 million customer records compromised by Microsoft. Mis-configured database.

For more than 3 weeks, 5 five Elasticsearch servers of Microsoft left 250 million customer support records publicly exposed. The misconfiguration was done on 5th December and was reported to Microsoft on 31st December after which all 5 servers were secured within 24 hours.

https://www.scmagazine.com/home/security-news/database-security/microsoft-database-misconfiguration-exposes-250m-customer-support-records/