In a straight party-line vote of 3-2, the Republican-controlled FCC junked the longtime principle that said all web traffic must be treated equally. The move represents a radical departure from more than a decade of federal oversight.
The big telecommunications companies had lobbied hard to overturn the rules, contending they are heavy-handed and discourage investment in broadband networks.
"What is the FCC doing today?" asked FCC chairman Ajit Pai, a Republican. "Quite simply, we are restoring the light-touch framework that has governed the internet for most of its existence."
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The push to eliminate net neutrality has stirred fears among consumer advocates, Democrats, many web companies and ordinary Americans afraid that the cable and phone giants will be able to control what people see and do online. But the broadband industry has promised that the internet experience for the public isn't going to change.
The FCC vote is unlikely to be the last word. Net neutrality supporters threatened legal challenges, with New York's attorney general vowing to lead a multistate lawsuit. Some Democrats want to overturn the FCC action in Congress.
"The fact that Chairman Pai went through with this, a policy that is so unpopular, is somewhat shocking," said Mark Stanley, a spokesman for the civil liberties organization Demand Progress. "Unfortunately, not surprising."
On Thursday, about 60 demonstrators gathered in the bitter chill of Washington to protest the FCC's expected decision. Just before the vote, the hearing room was briefly evacuated and searched for unspecified security reasons.
The FCC subscribed to the principle of net neutrality for over a decade and enshrined it in rules adopted in 2015.
Under the new rules approved Thursday, the Comcasts and AT&Ts of the world could slow down or block access to services they don't like or happen to be in competition with. They could also charge higher fees of rivals and make them pay up for higher transmission speeds. They just have to post their policies online or tell the FCC.
Such things have happened before. In 2007, for example, The Associated Press found that Comcast was blocking or throttling some file-sharing. And AT&T blocked Skype and other internet calling services on the iPhone until 2009.
Thursday's rule change also eliminates certain federal consumer protections, bars state laws that contradict the FCC's approach, and largely transfers oversight of internet service to another agency altogether, the Federal Trade Commission.
Angelo Zino, an analyst at CFRA Research, said he expects AT&T and Verizon to be the biggest beneficiaries because the two internet giants can now give priority to the movies, TV shows and other videos or music they provide to viewers. That could hurt rivals such as Sling TV, Amazon, YouTube or startups yet to be born.
However, AT&T senior executive vice president Bob Quinn said in a blog post that the internet "will continue to work tomorrow just as it always has." He said the company won't block websites and won't throttle or degrade online traffic based on content.
Internet companies such as Google, Twitter and Facebook have strongly backed net neutrality.
Netflix said in a tweet it is "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."
White House spokeswoman Sarah Huckabee Sanders said the Trump administration "supports the FCC's effort to roll back burdensome regulations. But as we have always done and will continue to do, we certainly support a free and fair Internet."
FCC Commissioner Mignon Clyburn, a Democrat appointed by President Barack Obama, lambasted the "preordained outcome" of the vote that she said hurts small and large businesses and ordinary people. She said the end of net neutrality hands over the keys to the internet to a "handful of multibillion-dollar corporations."
With their vote, she added, the FCC's Republican commissioners are abandoning the pledge they took to make a rapid, efficient communications service available to all people in the U.S., without discrimination.
But Michael O'Rielly, a GOP commissioner appointed by Obama, called the FCC's approach a "well-reasoned and soundly justified order."
The internet, he said, "has functioned without net neutrality rules for far longer than it has with them." The decision "will not break the internet."
New York Attorney General Eric Schneiderman, a Democrat, has been investigating what appear to be large numbers of fake public comments submitted to the FCC during the net neutrality comment period. He said 2 million comments were submitted under stolen identities, including those of children and dead people.