The makers of one of YouTube's biggest channels have dropped plans to trademark terms for a popular video format - after facing outcry from fans.
The Fine Brothers' "reaction videos" show people responding to online clips.
But a plan to license "react" to other video-makers was met with a digital backlash, costing the brothers hundreds of thousands of subscribers.
They have now apologised and said trademark applications will be rescinded.
"Hello, we're here to apologise," The Fine Brothers, Rafi and Benny, wrote in a blog.
Some of The Fine Brothers' most successful series include Kids React, Teens React and YouTubers React.
Videos in a similar style have been produced by many YouTubers - often with "react" in the title.
Among trademark applications filed by the brothers last year were the terms "Kids React", "Adults React" and the word "react" itself.
The duo responded to criticism that license agreements might be used to "police" online video by saying this was a "valid concern".
"Though we can assert our intentions are pure, there's no way to prove them," they added.
The trademark scheme, which they had named the React World program, has been discontinued, existing trademark applications have been rescinded and past YouTube copyright claims have also been dropped.
"This has been a hard week," the brothers wrote.
What is a reaction video?
In reaction videos, people - from children to celebrities - are shown an object or video clip and their response is filmed.
For example: a child in 2015 marvelling at the size of an old style printed encyclopaedia.
Because reactions like these are amusing to people who grew up with printed encyclopaedias, such videos tend to get shared widely on social media.
The format has been used by many others, including US chat show host Ellen DeGeneres.
What are trade marks?
Trade marks are the distinctive name or symbol used to identity a product made by a manufacturer or a good distributed by a dealer.
Trade mark law is generally concerned with avoiding consumer confusion regarding the origin or manufacturer of a product.
One YouTuber who had expressed disappointment over the trademark applications was Jon, from Many a True Nerd.
"I'm delighted, but not hugely surprised," he told the BBC after hearing about the U-turn.
"Given the huge subscriber number falls they've seen, sometimes over 10,000 lost subscriber per hour, the risk to their business was too great to ignore."
Jon added, though, that he felt The Fine Brothers would struggle to regain trust among those alienated by the episode.
"I think this movement and its consequences represent that YouTube as a community is quite determined to stay a free and open platform, and that makes me optimistic for the future," he said.
Ryan Morrison, a video gamer turned lawyer, had also been critical of The Fine Brothers' plans.
Previously, he had offered to support video-makers in a legal challenge to The Fine Brothers' trademark application.
"People were scared, and they were right to be," he told the BBC.
"I immediately offered to help, and the outpouring of support and willingness to join in my opposition filing was unlike anything I'd ever seen."