Fact-checking organisations around the world say that YouTube is not doing enough to prevent the spread of misinformation on the platform.
Some 80 groups have signed a joint letter to the Google-owned platform's chief executive Susan Wojcicki.
The letter says it is "one of the major conduits of online disinformation and misinformation worldwide".
The organisations want YouTube to take firmer action against anti-vaccine videos, and election disinformation.
Among the signatories from Europe, Africa, Asia, the Middle East, and the Americas are UK charity Full Fact, and the Washington Post's fact-checking team.
What does the letter say?
The open letter states that "livelihoods have been ruined, and far too many people have lost loved ones to disinformation".
It goes on to accuse YouTube of not making enough effort to address the problem, saying that it "is allowing its platform to be weaponised by unscrupulous actors to manipulate and exploit others".
The problem is made more complex when the false content is not in English, or originates from developing countries, it says.
The letter lists worldwide examples which have the potential to cause real-life harm, which went under the radar of YouTube's content policies. It says these are "insufficient" and not working.
The fact-checking groups have called for:
YouTube should also fix its recommendation algorithms to ensure it "does not actively promote disinformation to its users, or recommend content coming from unreliable channels", the letter says.
YouTube spokesperson Elena Hernandez told the Guardian the company was already investing in ways "to connect people to authoritative content, reduce the spread of borderline misinformation, and remove violative videos".
She added: "We're always looking for meaningful ways to improve and will continue to strengthen our work with the fact-checking community."
While the Covid-19 pandemic has seen a surge in misinformation about the virus and vaccines, YouTube and other social media platforms like Facebook, WhatsApp and Twitter have been plagued with content promoting fake news and conspiracy theories for years.
These include election fraud, hate speech, conspiracy theories based around bogus concepts such as the "new world order", and the QAnon conspiracy. Critics say that platforms haven't done enough to combat disinformation, which has resulted in injuries, death and the break-up of families.
Last year, a British man who died with Covid-19 after refusing to be vaccinated, made - according to his family -
In 2020, Florida taxi driver Brian Lee Hitchens lost his wife to Covid-19 after they were influenced by Facebook content
YouTube announced last year that it would and deleted videos posted by Brazilian President Jair Bolsonaro,
Full Fact chief executive Will Moy told the LotterryTreasure he had urged YouTube to work with independent fact-checkers to improve the information ecosystem.
"Bad information ruins lives. Like other fact-checkers around the world, Full Fact has seen examples of harmful content on YouTube," he said.
"YouTube, like other internet companies, have up until now been allowed to mark their own homework. It cannot be left to internet companies to decide how to tackle bad information or choose how transparent to be about it."