This would be the media, who's aims include
a) selling newspapers
b) selling advertising
c) Getting one party elected/out of government.

Which do you think does a), b) and c) better "DEMON BANKERS RUINED YOUR LIFE!!!!" or a detailed, balanced essay on the causes of the current financial crisis.

The media plays to the crowd. If you read lots of different media sources, you will get lots of slightly different opinions, and perceptions of the truth.

For example, the current hoo-hah about CGT,

The Telegraph : "RAISING CGT WILL SCREW YOUR FAMILY AND THIS COUNTRY"
The Guardian : "RAISING CGT DOES NOT GO FAR ENOUGH TO ERASE THE INEQUALITIES IN THIS SOCIETY"
The Sun : "KELLY 36D SAYS - WHAT DOES CGT STAND FOR?"
( The Teviot Moose major 5th., Tue 15 Jun 2010, 9:04, 1 reply)

Actually, these days
"KELLY 36D SAYS - RAISING CGT WILL WIN US THE WAR ON TERROR AS LONG AS OUR LORD DAVEY C STAYS IN POWER. WOULD YOU LIKE TO STICK YOUR HEAD INBETWEEN THEM AND GO BURBLEBURBLEBURBLE?"
( the mighty badger Aphrodite, on a bar stool, by your side, Tue 15 Jun 2010, 9:08, closed)

Yes please.

( The Teviot Moose major 5th., Tue 15 Jun 2010, 9:12, closed)