In journalism, mainstream media (MSM) is a term and abbreviation used to refer collectively to the various large mass news media that influence many people and both reflect and shape prevailing currents of thought. The term is used to contrast with alternative media. The term is often used for large news conglomerates, including newspapers and broadcast media, that underwent successive mergers in many countries. The concentration of media ownership has raised concerns of a homogenization of viewpoints presented to news consumers. Consequently, the term mainstream media has been used in conversation and the blogosphere, sometimes in oppositional, pejorative or dismissive senses, in discussion of the mass media and media bias. United States In the United States, movie production is known to have been dominated by major studios since the early 20th century; before that, there was a period in which Edison's Trust monopolized the industry. In the early 21st century, the music and television industries was subject to media consolidation, with Sony Music Entertainment's parent company merging their music division with Bertelsmann AG's BMG to form Sony BMG, and Warner Bros. Entertainment's The WB and CBS Corp.'s UPN merging to form The CW. In the case of Sony BMG there existed a "Big Five", later "Big Four", of major record companies, while The CW's creation was an attempt to consolidate ratings and stand up to the "Big Four" of American network (terrestrial) television (although the CW was actually partially owned by one of the Big Four in CBS). In television, the vast majority of broadcast and basic cable networks, over a hundred in all, are controlled by eight corporations: Fox Corporation, The Walt Disney Company (which includes the ABC, ESPN, FX and Disney brands), National Amusements (which owns Paramount Global), Comcast (which owns NBCUniversal), Warner Bros. Discovery, E. W. Scripps Company, Altice USA, or some combination thereof. Media mergers and concentration in the United States Over time the rate of media mergers has increased, while the number of media outlets has also increased. This has resulted in a higher concentration of media ownership, with fewer companies owning more media outlets. Some critics, such as Ben Bagdikian, assailed concentration of ownership, arguing that large media acquisitions limit the information accessible to the public. Other commentators, such as Ben Compaine and Jack Shafer, find Bagdikian's critique overblown. Shafer noted that U.S. media consumers have a wide variety of news sources, including independent