不過我來說一個美國的轉折點吧, 是裏根政府不再實施The Fairness Doctrine
https://www.reaganlibrary.gov/archives/topic-guide/fairness-doctrine
The Fairness Doctrine mandated broadcast networks devote time to contrasting views on issues of public importance. Congress backed the policy in 1954 and by the 1970s the FCC called the doctrine the “single most important requirement of operation in the public interest – the sine qua non for grant of a renewal of license.
The doctrine stayed in effect, and was enforced until the Reagan Administration.
這是老美們容易有information cocoons的一個重要原因之一