The US communications regulator has controversially voted to abolish net neutrality rules that guarantee equal access to the internet.
The decision had been widely expected despite a campaign led by tech giants to keep regulations in place.
Members of the Federal Communications Commission (FCC), led by its Republican chairman Ajit Pai, voted along party lines to repeal rules put in place by the Obama administration in 2015.
The vote was supported by the White House and protests were held outside FCC headquarters during its meeting, which was abruptly halted just before the vote "on the advice of security".
Some 22 million people had submitted comments ahead of the decision and opinion polls showed 83% of Americans opposed the changes.
Opponents say they could have a major impact on how Americans access the internet.
The rules had prevented major telecoms firms like Comcast, AT&T and Verizon from blocking or slowing access to certain websites or apps.
The internet service providers have promised that nothing will change with the rules gone and insist the web will be more free with less government regulation.
Mr Pai said: "What is the FCC doing today? Quite simply we are restoring the light-touch framework that has governed the internet for most of its existence.
"The sky is not falling. Consumers will remain protected and the internet will continue to thrive."
Mr Pai has called the internet the "greatest free-market innovation in history" and mocked "heavy-handed government regulation" for not being helpful to the web's growth.
And White House press secretary Sarah Sanders told reporters: "The administration supports the FCC's efforts and at the same time the White House certainly has and always will support a free and fair internet."
Entertainment companies and tech giants like Google, Facebook, Spotify and Netflix had been among those who pressured the FCC to leave the rules in place.
Netflix tweeted that it was "disappointed" with the decision to "gut protections that ushered in an unprecedented era of innovation, creativity and civic engagement".
The decision is now likely to face legal challenges.
New York attorney general Eric Schneiderman has promised to lead a multi-state lawsuit. He said the vote was "a blow to New York consumers and to everyone who cares about a free and open internet."
The fear amongst opponents is that service providers, increasingly becoming content providers themselves as well, could prioritise access to their own brands.
We’re disappointed in the decision to gut #NetNeutrality protections that ushered in an unprecedented era of innovation, creativity & civic engagement. This is the beginning of a longer legal battle. Netflix stands w/ innovators, large & small, to oppose this misguided FCC order.
— Netflix US (@netflix) December 14, 2017
They say websites could be charged more to reach consumers.
But those companies have tried to reassure internet users, denying they will degrade traffic.
AT&T senior executive vice president Bob Quinn said: "The internet will continue to work tomorrow just as it always has."
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Commissioner Mignon Clyburn, a Democrat who was appointed by President Obama, voted against the change.
She said it would hurt individuals, marginalised groups and businesses, adding that it would also hand the keys to the internet to "a handful of multi-billion dollar corporations".