The media is changing over period of time it becomes more global. The rise of a global oligopoly not only happened to the oil and automotive but it's also happening now to the entertainment industry. This global media was encouraged by new digital and satellite that make global market more cost-effective and more lucrative or profitable. However, the rise of this global media does not mean to be better. In fact it is worsen the working of perfect democracy that is, political system based on the formal right to vote.
Since media system deviated by the late 1990s the media has primarily goes national and even global. This turning point will bring the media system to the next step. For example U.S. media system have global version in order to broadcast internationally. This global version will affect other country such as Norway,Denmark, Mexico, Spain, South Africa, and South Korea in their domestic film production. This will issue lack of diversity of news and TV programmes. .
Furthermore, giant U.S supermedia firm such as Time Warners, eventually will merge with other supermedia such AOL and forming even monstrous media company. This will set exceptionally high barrier to prevent new or other company to join the the supermedia circle. Thus this will produce lack of competition and lead to again, lack of diversity on news and TV shows.
On the other hand, global media can advantage to favour political leader. For example Rupert Murdock manipulate his British newspapers" to support Tony Blair to become Prime Minister in 1997 election. Clearly by manipulation of newspaper it does not represent true public view and this is violating the perfect democracy rules where people have equal rights to speak and to vote.
In conclusion, new global media may blinded and deceiving people from the truth. Likewise, global media will produce less competition making more like oligopoly, thus will result lack of diversity as well as lack of public opinions.