Fabrication of politically sensitive incidents

It has been reported that right wing political groups have planted bombs in order to be able to argue that action should be taken against left wing terrorists or illegal immigrants supposedly responsible for such incidents. Similarly religious and other extremists are reported to put slogans on walls critical of themselves or of their opponents (eg the Swastika or Star of David) in order to arouse support for their cause or to provoke concern for the influence of their opponents.