AT&T has been data-mining and willingly sharing user phone data, through its Hemisphere Project, which is essentially a mass surveillance program. The company has collected and retained, in the past, phone call logs and other Metadata with of extensive 380 million user database. Research conducted by the NSA revealed that telephone metadata can reveal sensitive personal information of the user. The revenue for such a service amounts to millions per year, according to the report.”]
Source: http://securityaffairs.co/wordpress/52921/intelligence/att-mass-surveillance.html