Apple co-founder Steve Wozniak is suing YouTube for allegedly allowing scammers to use images and videos of him to defraud people.
The scam, similar to one used in a Twitter hack, requested people send cryptocurrency, falsely promising they would receive twice as much back.
Mr Wozniak accused YouTube of failing to deal with the problem.
YouTube and Google have been contacted for comment but have not yet responded.
The complaint alleges the “vast” scam is continuing on YouTube, with tens of millions of dollars in cryptocurrency stolen.
As well as Mr Wozniak, the law firm Cotchett, Pitre and McCarthy is also representing 17 others affected by the fraud, from the US, UK, Canada, Japan, Malaysia, China and Europe.
In a statement, Mr Wozniak said: “If YouTube had acted quickly to stop this to a reasonable extent, we would not be here now.
“YouTube, like Google, seems to rely on algorithms and no special effort requiring custom software employed quickly in these cases of criminal activity.
“If a crime is being committed, you must be able to reach humans capable of stopping it.”
It is hard to estimate how widespread such scams are.
But last month, fraudsters stole at least $150,000 (£117,000) by impersonating Elon Musk’s Space X YouTube channel and hosting a live-streamed event asking viewers to send Bitcoin.
And a report from cryptocurrency monitoring service Whale Alert suggested scammers made $24m in Bitcoin during the first six months of 2020.
Lawyer Joe Cotchett. who is representing Mr Wozniak, compared the YouTube scam to the recent Twitter hack.
“When Twitter was hit with a massive hack of 130 celebrity accounts, they were quick to shut down the Bitcoin scam in a day,” he said.
“In stark contrast, the complaint alleges that YouTube knowingly allowed the Bitcoin scam to go on for months promoted it and profited from it by selling targeted advertising.”
In a similar case brought by cryptocurrency company Ripple Labs, YouTube’s legal team successfully argued the platform was not liable for any content – including scams – provided by third parties.