With the increase of terrorist attacks and spreading extremism worldwide, countermeasures advance as well. Often social media is used for recruitment and radicalization of susceptible target groups. Counter narratives are trying to disclose the illusion created by radical and extremist groups through a purposive and educational counter statement, and to initiate a rethinking in the affected individuals via thought-provoking impulses and advice. This exploratory study investigates counter narrative campaigns with regard to their fight and prevention against terrorism in social media. Posts with strong emotions and a personal reference to affected individuals achieved the highest impact and most reactions from the target group. Furthermore, our results illustrate that the impact of a counter narrative campaign cannot be measured solely according to the reaction rate to their postings and that further analysis steps are therefore necessary for the final evaluation of the campaigns.