Mass Media/Influence of Media
Mass media plays a huge role in politics. One example was Arnold Schwarzenegger's campaign for governor of California, where he was portrayed as a candidate with a serious demeanor, but a hedonistic past.
The Mass Media also determines what issues are discussed by the populace, by putting certain news stories into the limelight. News is separated into two categories, hard news (such as politics, foreign affairs, and other serious issues), and soft news ("entertainment" news, like celebrity gossip, and scandals). Sometimes, a hard news story will replace a softer one for dominance. The Gary Condit scandal was forgotten after the World Trade Center disaster.
The outlook on an issue is called the "spin." One of the most obvious examples of spin is the types of terminology groups use for themselves and their opponents. Anti-abortion activists refer to themselves as "pro-life" and their opponents as "anti-life", while pro-abortion groups call themselves "pro-choice" and their opponents "anti-choice." This is a very basic example of spin. Although news media is not supposed to have any spin, the choice of wording for a story can affect how it is perceived.
A large topic of research for sociologists is Media Effects. The media can create distortion. For instance, an emphasis on reporting child abductions may cause the populace to believe that kidnapping is on the rise, when the truth may be just the opposite.
One of the most powerful effects of media is "agenda setting." Mass media cam indirectly create policy. By focusing on certain types of stories, politicians can be influenced. For example, when Roy of Siegfried & Roy was mauled by their tiger, it was a big story. Soon, similar stories surfaced in the news, such as one where a man was bit by a tiger he kept in his apartment. Soon, a bill was put before Congress to restrict domestication of big cats.
Stereotyping is aided by mass media. A simple stereotype follows the form "All X are Y." These form the basis of prejudices, which can be very harmful to a society. A stereotype can be applied to people, places, or things. If something is portrayed the same way many times in the media, the message will be enforced through repetition. Some people will believe it is true, especially if their only link with the thing is through mass media. For instance, people whose experience with African-Americans is primarily made up of negative media impressions (such as gangsta rap and gangland films) will probably have a negative prejudice towards blacks.
However, media can also give us access to cultures we may never see otherwise.
Public Relations 
A huge part of media use is for Public Relations (PR): persuasive messages used to influence the populace's opinion of a person, organization, or product. Corporations and other organizations often use advertising for PR, but many other types of media are also used. For example, the US government and other groups sometimes use the Fourth of July as a PR effort to induce patriotism.
George Washington recruited Thomas Paine to write the Crisis Papers, which he read to the US troops. They went on to a great victory.
P.T. Barnum used PR for huckstering.
Teddy Roosevelt was the first US president to hire a press secretary. Journalists followed his "Rough Riders."
Rockefeller broke up striking miners with gunfire. The media called it a "massacre." He hired Ivy Lee (the "Father of Public Relations") to improve his image.
It was Edward Bernays who established PR as an industry, and wrote the first PR book. He was called the "Master of Spin." When a hair net company came to Bernays with poor sales, he helped by urging labor commissioners to require female workers to wear hair nets in the interest of safety and hygiene. His campaign was successful. 
All organizations have PR. PR is used in the military to indoctrinate soldiers.
PR activities include issuing press releases, various community work, and media manipulation. PR workers believe that "journalists report bad news, PR men report good news."
Press releases are papers written like a news article. They are sent to media outlets in the hope of getting them turned into news stories. They may be part of a press packet, which contains supporting material, such as a videotape for TV news.
Press conferences are meetings of organization spokesmen with various members of the media. The spokesmen discuss issues in the hope of getting into the news. A pseudo-event is a staged event for PR purposes.
Two important rules for PR are to break a story right before the newscast and to never lie.