The existing US definitions of Open Source Intelligence (OSINT) are severely deficient at multiple levels. See the official definitions below the line. Here is a proper definition devised with Joe Markowitz and others who actually know something about the discipline.
Open Source Intelligence (OSINT) is decision-support (an output not an input) that integrates open sources and methods including all forms of direct human knowledge elicited by intermediaries without subterfuge. It combines direct access to indigenous humans, gray literature, and the deliberate exploitation of both published and unpublished (field) human experts, advanced multi-disciplinary and multi-domain processing and integration or deconfliction, and advanced visualization and other methods for communicating context and insight to the supported decision-maker(s). OSINT is not the same as Open Source Information (OSIF), which is where the official definitions are now–publicly available information, nor is it the same as Open Source Data (OSD) or Validated Open Source Intelligence (OSINT-V), which can only be produced by an all-source analyst generally not a contractor. OSINT is a human intelligence function, not a technical intelligence function.
OSINT has been superceeded as the center of gravity for the future of intelligence by M4IS2: Multinational, Multiagency, Multidimensional, Multidomain Information-Sharing and Sense-Making. 90% of M4IS2 is not secret, not expensive, and not federal or controlled by any government. Outside the wire both OSINT and M4IS should be controlled by the J-3 via Civil Affairs (Human) and Information Operations (IO). Secret bureacracies (including “cyber-commands”) do not have the knowledge, mind-set, or reliability to manage OSINT and M4IS2 interactions with all manner of humans in every clime and place. Inside the wire, the J-2 becomes the integrator of all-source information, and Civil Affairs and IO become advisory functions to the J-3 on non-kinetic options.