Social media exploitation by state and non-state actors has an increasingly visible effect on the contemporary operating environment (COE); relating to national security as well as political systems and democracy in general. No case shows this clearer than ISIS social media exploitation and this case was crucial for operations leading to the largest effect any armed, non-state actor likely every produced on global security perceptions. How exactly did ISIS use social media to achieve this effect? After an introduction to relevant characteristics of social media for the (COE), this chapter briefly introduces the first prominent case of social media exploitation for security operations, the “Twitter War” between the Israeli Defense Force (IDF) and Hamas in November 2012. This chapter then goes on to explain how ISIS exploits social media in the South-Eastern European (SEE) and concludes by identifying challenges for the COE that come through armed, non-state actor social media exploitation. Social media is a highly effective tool for influence operations: however, with it come significant challenges that have to be manage not only from a national security perspective, but also for democracy.