‘It happened again today,” Bria Kam tells me, throwing her arms up in frustration. I am speaking to Kam and her wife, Chrissy Chambers, over FaceTime from their home in Vancouver, Washington. They are sitting in their workout gear, on the familiar grey couch where they record the YouTube videos that have turned them into stars. But there are no signature dazzling smiles today.

This morning, the couple uploaded a video called Ten Ways to Know You’re in Love (Do You Want a Baby?), a benign collection of comedy sketches (including one in which Chambers falls asleep while Kam is talking, and another in which Chambers is going through her rock collection) followed by an interview with a lesbian couple who had conceived a child with donor sperm.

“The second it went live it was age-restricted and demonetised,” Kam says. Age-restricted videos cannot be found using YouTube’s search engine, and can only be watched by people who have signed in to a YouTube account and given their age as over 18 – which means many of the pair’s core teenage audience would not be able to see it. Demonetised means YouTube has decided the content is “unfriendly” for most advertisers, so Chambers and Kam will also not be making any advertising revenue from it.

It happened so quickly that there was no way the decision could have been made by a person: there was no time for anyone to have watched the video. So why did it happen? Chambers and Kam think they know; YouTube’s algorithm, they believe, is discriminating against them.

YouTube has turned Kam and Chambers into stars. Kam, 32, is a singer-songwriter who once appeared on American Idol; Chambers, 28, is an actor and personal trainer. They have been together since 2011 and married last year. The pair uploaded their first YouTube video in 2012, expecting only their mothers to watch it, but their second video, a comedy protest song they wrote about the fast-food restaurant Chick-fil-A after the chain’s CEO condemned same-sex marriage, went viral. It made them realise there was a living to be made on the platform.

More than a million people now subscribe to their two YouTube channels: a mix of comedy, music and self-help videos. It has made them among the best-known lesbian duos on the platform. In other words, for the past seven years, YouTube has given them a career, an income and hundreds of millions of young, female viewers.

But today they have joined six other LGBT YouTube stars to file a class action lawsuit against the platform and its owner Google, suing them for “discrimination, fraud, unfair and deceptive business practices” and “unlawful restraint of speech”.

This is because the group say that the YouTube algorithm – purpose-built software that YouTube relies on to recommend, censor and place advertising on videos – discriminates against LGBT YouTubers purely because they produce LGBT content.

Algorithms use automated reasoning to cut through swathes of data – data sets too large for any human to analyse – to make decisions. They are everywhere: recommending content on Spotify; making suggestions for future purchases from Amazon; telling Netflix what kind of original content to commission; and used by banks to decide if you should have a mortgage. They are not only ubiquitous and unseen but also very powerful. And in an age in which increasingly mighty tech giants leave it to algorithms to decide who gets access to audiences, the LGBT class action against YouTube is significant for all of us, regardless of our sexuality. If software that is supposed to be neutral is already discriminating against entire communities, who will be next?

In the complaint filed against YouTube and Google today, YouTube is said to have become “a chaotic cesspool where popular, compliant, top-quality and protected LGBTQ+ content is restricted, stigmatised and demonetised as ‘shocking’, ‘inappropriate’, ‘offensive’ and ‘sexually explicit’, while homophobic and racist hatemongers run wild and are free to post vile and obscene content on the pages and channels of LGBTQ+ plaintiffs and other LGBTQ+ content creators or audiences”.

Kam and Chambers got married in 2018. Photograph: Publicity Image

YouTube’s CEO, Susan Wojcicki, gave a video interview to the British YouTuber Alfie Deyes this month in which she responded to claims that LGBT content was being demonetised. “We do not automatically demonetise LGBTQ content,” Wojcicki said. “We work incredibly hard to make sure our systems are fair. We have an ML fairness initiative – ML stands for Machine Learning – to make sure our algorithms, and the way that our machines work, are fair. We have a committee and a whole process to make sure that we are managing fairness of how our algorithms work.”

This is not Kam and Chambers’ first campaign. They made legal history last year when Chambers won unprecedented damages against a British man who uploaded “revenge porn” videos of her online. It was the first civil case of its kind in England and Wales. Now they are taking on one of the world’s most powerful corporations in another landmark lawsuit.

The pair first suspected something was wrong in 2013. “YouTube said: ‘We’re going to be doing this big LGBT campaign, so we want you to make a video called #ProudtoLove, and just talk about what it’s like to be in a relationship with your partner,’” Kam explains. “We jumped on it.”

The video initially did well, but a couple of years later they discovered it had been demonetised. “We are absolutely confused by how they could have asked us to create content that they were then going to punish us for.” Kam used YouTube’s automated system to appeal, but got a notification saying that their appeal was ineligible. After they complained on Twitter, a YouTube staffer responded and promised to fix the problem. “Within seconds it was monetised again,” Kam says.

Their videos might sometimes be cheeky, but Kam and Chambers make them with teenagers in mind, and their content is always intended to be gentle. Yet when Kam holds up her iPhone to show me their channel’s user page, only three out of seven videos are monetised. (Four days later, Kam emails to say the Ten Ways to Know You Are in Love video has been remonetised: “I’m assuming a human went back and approved it,” she writes.)

Some of the most inoffensive videos the duo have made have been immediately age-restricted by YouTube (including a music video that involves nothing more controversial than Chambers walking around, fully clothed, in the desert), which denies them key viewers. “Age restriction means we can’t reach the young women who look up to us, who need us as a sense of community and support,” says Chambers. “We’re not able to be there and give that to them.” Interaction with their fans in the comments section, over private messaging and even live over Skype is a core part of their work, they say. For young people questioning their sexuality, videos created by LGBT YouTubers can demonstrate that a visible, vibrant LGBT community exists. The pair have lost count of the messages they have had from suicidal young people who have found comfort in their channel. “When I think about YouTube shutting down our content, it gets me all fired up because they are literally having an impact on someone living another day,” Chambers says.

Kam and Chambers also have questions about how much the YouTube algorithm thinks they are worth. The rate a YouTuber is paid per thousand views varies according to the age, location and gender of their audience, and the type of content that audience normally watches. It is a mysterious and constantly changing formula known as the “cost per mille” (CPM): the amount advertisers pay per thousand views. PewDiePie, the gaming video-maker who is one of YouTube’s biggest stars, for instance, makes more than $20m (£16.5m) a year from the platform.

“We have some of the lowest CPMs ever seen,” says Kam. “I think it’s because we are lesbians and our demographic is poor lesbians. If we made makeup videos or gaming videos, we could be millionaires by now. We’re getting 4-5m views a month and we’re getting $4-500 [£250-330] a month.”

A few years ago they could earn a living just from the revenue they got from YouTube ads; changes to the CPM and algorithm now mean they rely on sponsorship, live streaming on other platforms where they interact with viewers in real time and Patreon, where fans pay them a monthly donation in exchange for regular postcards, Skype chats or personalised videos.

Yet while their videos are often demonetised, some groups can pay to have homophobic advertising placed on LGBT content. Like several other plaintiffs in the class action case, Chambers and Kam have found anti-gay marriage ads put at the start of their videos. “That’s not a coincidence,” Kam says. And while the algorithm will censor their videos the moment they are uploaded, it won’t remove offensive comments users post underneath them. It is commonplace for their comments section to be inundated with homophobic abuse – which they have to police themselves.

Kam and Chambers are not sure why all this is happening. “I think YouTube are scared that advertisers will leave and, because they think LGBT is controversial, they are trying to nip it in the bud,” Kam says. Chambers feels YouTube is trying to push independent LGBT contributors off the platform. “They want viewers to watch the gay content they create through their studios, not the gay content that individual gay creators create. They are becoming more and more controlling.”

After seven years of trying to speak to a real person at YouTube, Kam and Chambers finally talked to a YouTube partner development manager this year. “It was all excuses, corporate jargon. Nothing changed,” says Chambers.

A still from the #ProudtoLove video the duo made for YouTube in 2013. Photograph: Youtube/BriaAndChrissy

Yet the idea that YouTube might be discriminating against LGBT content creators is not new. In March 2017, #YouTubePartyIsOver was trending on Twitter after several prominent YouTubers complained that videos of same-sex couples exchanging vows and makeup tutorials for trans women were being age-restricted. In September 2017, the bisexual author and comedian Gabby Dunn tweeted that all the LGBTQAI content on her channel had been demonetised while the heterosexual content had not.

YouTube admitted at the time that its system “sometimes makes mistakes” and that restricted mode “isn’t working the way it should. We’re sorry and we’re going to fix it.” It blamed an engineering problem, saying the algorithm “should not filter out content belonging to individuals or groups based on certain attributes like gender, gender identity, political viewpoints, race, religion or sexual orientation”. But it seems problems remain.

In the Deyes interview, Wojcicki insisted the company is supportive of LGBTQ creators. “The community has been an incredibly important part of YouTube,” she said. “We have so many creators who have come from that community, and we are really proud that we have been able to assist so many youth who otherwise might have felt more isolated to be able to have a better understanding and connection to the LGBTQ community.”

It is only a year after Chambers won her victory in her revenge porn case, a four-year legal battle that left both her and Kam emotionally exhausted. Why go back to court now, to take on an even bigger Goliath? “I’ve always wanted to be someone who stood up to the bully,” Chambers says. “We are not going to let a corporate predator silence our ability to make a difference to the people who gave us this platform in the first place. We’ll never stop making content, whether we’re making money or not.

“When I die, I want to be able to say: ‘I might not have made a ton of money, but at least I have made a difference.’”