According to reporting by Catalin Cimbanu for ZDNet, "On Monday, a security researcher specialized in finding exposed databases has identified an unsecured MongoDB server that was leaking the personal details of nearly 11 million users. The server appears to belong to an email marketing firm based in California.
The data, contained in a 43.5GB dataset, included full names, email addresses, gender information, and physical addresses such as state, city, and ZIP code for 10,999,535 users.
All email addresses contained in this database were Yahoo-based, suggesting this was only a small part of a larger dataset, most likely stored on multiple servers.
. . .
While initially it was not clear who was the owner of this database, one small suffix in several records --such as "Content-SaverSpy-09092018"-- suggested this data may belong to a company named SaverSpy.
Combining a simple Google search along with the nature of the user records found in the exposed database led both this reporter and Diachenko to believe the data belonged to SaverSpy.com, a daily deals website. The SaverSpy.com website claims to operate under the Coupons.com brand, but a Quotient spokesperson told ZDNet today that SaverSpy is only part of an affiliate program."