Scapegoating is an important tool of propaganda. For example, in Nazi Germany the Jews were singled out as the source of Germany's economic woes and political collapse.
Scapegoating is almost always applied to a minority group, as they will by definition be in the minority, and thus find it difficult to defend themselves.
Recently, mostly applied to the Director of Financial Reporting at SCO group.
Some other common "scapegoated" minorities throughout history have been blacks, immigrants, Communists, and gypsies.
Compare: moral panic; hue and cry; witchhunt