National Security Agency has built ICREACH, a Google-like search engine that secretly provides data metadata of both foreigners and citizens on US soil to nearly two dozen U.S. government agencies, including the DEA, FBI, and CIA. Many of those surveilled data had not been accused of any illegal activity as well, according to classified documents disclosed by former intelligence contractor Edward Snowden. Knowing those 850 billion metadata, one can track people’s movements, map out their networks of associates, predict future actions, and potentially reveal religious affiliations or political beliefs.
Source: https://thehackernews.com/2014/08/icreach-nsas-secret-google-like-search_25.html