The term "fake news" took on a whole new meaning and set of consequences following the 2016 U.S. presidential election. One of the biggest stories following the election was the chaos wrought by so called “fake news” articles and publications.
Today people often call it by another name, propaganda. Using widely distributed media that tells half-truths in order to influence public opinion has been going on since Darius I took the Persian throne in 515 BCE. In America it's been around since the days of yellow journalism and perhaps before.
The goal of propaganda and fake news is often to damage the reputation of a group, individual, or idea. By discrediting something, the party responsible for the distribution of lies gains power over the people who believe in these falsehoods. At the same time, the tarnished reputation serves to repulse supporters and diminish their ability to grow support.