OSINT

Wikipedia: " OSINT is a highly diverse form of intelligence collection and analysis. It does not have its own agency, however, units are scattered within the Department of Defense and the State Department. Most OSINT collectors need to take precautions while collecting information from the Internet. This can come in the form of using a VPN to anonymize their identity and collect information more discreetly. This is where evaluating sources becomes important to the overall OSINT collection and analysis process. An OSINT analyst needs intelligence evaluation to determine a true process or expose a false process that would affect predicting the future. Finally, the analysts need to find use of the evaluated intelligence so that it can be incorporated into a finished classified, unclassified, or proprietary intelligence product.
See also: Big Data"

"Information collection in OSINT is generally a different problem from collection in other intelligence disciplines where obtaining the raw information to be analyzed may be the major difficulty, particularly if it is to be obtained from non-cooperative targets. In OSINT, the chief difficulty is in identifying relevant, reliable sources from the vast amount of publicly available information. However, this is not as great a challenge for those who know how to access local knowledge and how to leverage human experts who can create new tailored knowledge on the fly."