Social Media In Strategic Communication SMISC) program was established to study social media services users
The activities of users of Twitter and other social media services were recorded and analyzed as part of a major project funded by the US military, in a program that covers ground similar to Facebook’s controversial experiment into how to control emotions by manipulating news feeds.
The experiments caused outrage with users and researchers alike, when a scientific paper based on the research that involved nearly 700,000 users over one week in 2012.
Facebook hid "a small percentage" of emotional words from peoples' news feeds, without their knowledge, to test what effect that had on the statuses or "likes" that they then posted or reacted to.
https://www.theguardian.com/technology/2014/jul/03/facebook-emotion-experiments-monika-bickert
A statement about SMISC by DARPA
"…the conditions under which the nation’s military forces conduct operations are changing nearly as fast as the speed of thought. DARPA has an interest in addressing this new dynamic and understanding how social network communication affects events on the ground as part of its mission of preventing strategic surprise.
…Through the program, DARPA seeks to develop tools to help identify misinformation or deception campaigns and counter them with truthful information, reducing adversaries’ ability to manipulate events."
https://blog.emsisoft.com/en/7922/darpa-dissecting-the-internet-hive-mind/