The Republican-led Federal Communications Commission voted Thursday to approve a controversial plan to repeal Obama-era net neutrality protections. The repeal passed 3-2, along a party-line vote.

The vote came amid mounting protests from the tech industry, consumer advocacy groups and even some Republican members of Congress who’d urged the FCC to delay or cancel the vote.

In what may be a sign emotions running high on the issue, the net neutrality vote was briefly interrupted due to a security threat. FCC commissioners and the audience were forced to evacuate the room.

“Sorry for the interruption,” Ajit Pai, the chairman of the FCC, said after returning to the room. “We were acting on the advice of the federal protection service. Where was I?”

The net neutrality rules, approved by the FCC in 2015, were intended to keep the internet open and fair. Internet service providers like Comcast and Verizon were explicitly prohibited from speeding up or slowing down traffic from specific websites and apps.

Under the approved proposal, the FCC would do away with rules barring internet providers from blocking or slowing down access to online content. The FCC would also eliminate a rule barring providers from prioritizing their own content.

Pai, appointed to run the FCC by President Trump, has been a longtime critic of the net neutrality rules. Last month, he pitched his repeal proposal as a way stop the federal government from “micromanaging the internet.”

“It is not going to destroy the internet. It is not going to end the internet as we know it. It is not going to kill democracy. It is not going to stifle free expression online,” Pai said in his remarks Thursday.

Pai’s plan has been praised by the telecom industry, which argues the earlier regulation was a drag on broadband investment and innovation. In a blog post this week, Comcast downplayed concerns, saying customers “will continue to enjoy all of the benefits of an open Internet today, tomorrow, and in the future. Period.”

But net neutrality advocates have sounded alarms that the repeal could give internet providers too much control over how online content is delivered. It may also make it harder for the next generation of online services to compete, if they have to pay up to be placed in a so-called internet fast lane.

Related: The end of net neutrality: What it all means

Demonstrators gathered outside the FCC building on Thursday and piled flowers on the ground in an apparent memorial for the internet as we know it.

Twitter, Reddit, Kickstarter and other websites posted messages on their sites this week ahead of the vote in support of net neutrality. Protesters mobilized in front of Verizon stores around the country. And some of the creators of the internet penned a letter calling on the FCC to cancel the vote.

“The internet industry opposes Chairman Pai’s repeal of the 2015 Open Internet Order,” Michael Beckerman, president and CEO of the Internet Association, a trade group representing Amazon, Facebook, Google and other tech companies, said in a statement Thursday. “Relying on ISPs to live up to their own ‘promises’ is not net neutrality and is bad for consumers.”

On the eve of the vote, Pai attempted to play down these concerns with a series of playful videos in partnership with a conservative news site, suggesting Americans will still be able to binge watch and make memes without net neutrality.

The issue may ultimately end up being decided in court. Congress can also choose to pursue a legislative solution.

A coalition of net neutrality advocacy groups is now shifting to petitioning Congress to overturn the FCC vote. The Internet Association said it’s also weighing legal options.

“While the fight to preserve net neutrality is going to be longer than we had hoped, this is far from over,” Alexis Ohanian and Steve Huffman, the cofounders of Reddit, wrote on Thursday.

“We’re disappointed in the decision to gut #NetNeutrality protections that ushered in an unprecedented era of innovation, creativity & civic engagement,” Netflix said in a tweet after the vote. “This is the beginning of a longer legal battle.”

No matter what happens next, the repeal won’t take effect until next year. It must first be formally approved by the Office of Management and Budget. An FCC representative told CNNMoney the process could take “several months.”

Ahead of the vote, some Republicans also expressed concerns with Pai’s plan. Sen. Susan Collins, a Republican from Maine, joined Sen. Angus King, an independent, in issuing a last-minute call Thursday for Pai to cancel the vote.

“This is a matter of enormous importance with significant implications for our entire economy and therefore merits the most thorough, deliberate, and thoughtful process that can be provided,” the senators wrote in a letter. “The process thus far in this important matter has not met that standard.”

The repeal vote comes more than six months after the FCC kicked off the lengthy process to roll back the net neutrality protections. It received millions of comments during a review period, with the majority supporting the current protections.

There has also been mounting scrutiny in recent weeks over rampant fraudulent comments submitted during the review period. New York Attorney General Eric Schneiderman said last month the FCC had been uncooperative in his office’s investigation into the comments.

“I dissent from this rash decision to roll back net neutrality rules. I dissent from the corrupt process that has brought us to this point. And I dissent from the contempt this agency has shown our citizens in pursuing this path today,” Jessica Rosenworcel, one of two Democratic commissioners at the FCC, said in a statement Thursday.

“This decision puts the Federal Communications Commission on the wrong side of history, the wrong side of the law, and the wrong side of the American public.”