Open-source intelligence (OSINT) involves accessing, gathering, and analyzing publicly available information for intelligence purposes and has applications in both hacking and detective work. The text describes how OSINT is used by hackers to analyze data about organizations and technologies, and by detectives to investigate individuals' activities. It highlights notable cases such as the Luka Magnotta investigation, where internet sleuths used social media and digital footprints to aid authorities in capturing a criminal. The document also emphasizes the importance of social media in creating digital profiles and the risks associated with a loose digital footprint, as seen in examples like the war in Ukraine. It discusses how successful OSINT analysts can distinguish impactful information, such as internal documents and server configurations, and stresses the need for ethical reporting in bug bounty and hacking contexts.