The Android caller ID app Dalil exposed online data belonging over 5 million users, security experts discovered a MongoDB database left accessible on the web without a password. The database contained cell phone numbers, App registration data (full name, gender, etc.) device info (vendor, model, serial number, MAC address, SIM number, IMEI, OS version, others), telecom operator details, GPS coordinates for some users and logs of the users activity (Individual call details and number searches)”]
Source: https://securityaffairs.co/wordpress/82233/data-breach/dalil-data-leak.html