We have to protect the American people from misleading or false information spreading from news sources. It is only when we are truthfully informed that we can make the best decisions for our country.
The United States is run by the people. We are the voters and we are the ones that politicians have to appeal to. A misinformed public will lead to misinformed decisions which in turn make a weaker nation.
And this nation has reached a point where we have multiple groups scouring over news searching for lies and misleading information. But many do not know of those groups and those who do shouldn't have to get their news from there.
Links for more information:
http://en.wikipedia.org/wiki/Media_bias_in_the_United_States