Mine social media
An adversary may research available open source information about a target commonly found on social media sites such as Facebook, Instagram, or Pinterest. Social media is public by design and provides insight into the interests and potentially inherent weaknesses of a target for exploitation by the adversary. 
Detectable by Common Defenses (Yes/No/Partial): No
Explanation: Searching publicly available sources that cannot be monitored by a defender.
Difficulty for the Adversary
Easy for the Adversary (Yes/No): Yes
Explanation: Very public by design. Application of privacy settings is not a panacea.
- Rotem Kerner. (2015, October). RECONNAISSANCE: A Walkthrough of the “APT” Intelligence Gathering Process. Retrieved March 1, 2017.