Billions of records belonging to a database maintained by cloud platform BlueKai were left exposed online due to a security lapse , according to a TechCrunch report . BlueKai , a startup acquired by Oracle in 2014 maintains a large database acquired through web tracking . It is meant to map user trends online in order to help marketers target potential consumers , the report said . BlueKai uses website cookies and other tracking technology to track user activity on the web . The data is meant to help advertisers create targeted ads . However , due to a security lapse in one of the servers which were left without a password , billions of records from a database were exposed online . The data breach was discovered by security researcher Anurag Sen who the reported his findings to tech major Oracle through Roi Carthy , chief executive at cybersecurity firm Hudson Rock , the report said . TechCrunch then reviewed the data shared by Sen. The data contained records of personal information including names , home addresses , email addresses and other identifiable data . Some of the records were detailed enough to trace back a person based on their online activity . In one instance , TechCrunch based on the records was able to trace back a € 10 bet on an esports betting site on April 19 back to a man in Germany with details including his name . The data also contained web browsing activity ranging from online purchases to newsletter unsubscribes as per the report . ;