Media bias: the slant in presentation of news in a way that favors one side or group in society over another, or towards predetermined ends; this may include suppression of information, unbalanced reporting, misrepresentation or over-representation of facts, and use of emotionally loaded words or images to influence public perception.
Stereotype: a widely held but fixed and oversimplified image or idea of a particular type of person or thing, especially when used to justify prejudice or persecution.