MoneySavingExpert founder Martin Lewis is to sue Facebook over scam adverts using his image.
The commentator and financial journalist is claiming defamation over allegations that the site is publishing scam adverts using his image causing vulnerable people to hand over thousands of pounds to criminals.
He said the company had hosted more than 50 of the scam ads and that it had failed to act because it was motivated by "greed".
Mr Lewis said the legal action, due to be launched on Monday, was the result of months of frustration with scammers who were piggybacking on his reputation and preying on Facebook users with outlandish get-rich-quick scams.
Supporters have handed over thousands of pounds in good faith, only to find the advert has nothing to do with Mr Lewis or his company.
"Vulnerable people are the ones being scammed and the ones being hurt," he told the Daily Telegraph. "It has to take some responsibility."
"It is not worth Facebook's while improving its systems. The company who is the leader in facial recognition, when it's been put on notice by someone that there is a scam and that that person never does adverts, it is not beyond its wit and wisdom to notify me of these adverts, and ask if they are legitimate.
"But its processes don't work like that - it wants to make it flexible and easy for anyone to be able to advertise - and it has done, including criminal scammers.
"Facebook has become this big agglomerated organisation where no-one seems to take care and responsibility."
Any damages won through the lawsuit will be donated to charity, by Mr Lewis said the legal action was not designed to win the case itself, but to force the company to change its policy on advertising, for example by having inbuilt settings notifying well-known people every time their image was used in an advert, requiring their approval.
It's distressing, and genuinely makes me feel physically sick when I hear someone has lost money because of this, and because they trusted me, and now they blame me.
He said he has repeatedly reported the adverts, only for new, almost identical ones to appear days later.
"I don't do ads, so an ad with me in it, does not have my permission. These are companies warned about by the FCA, warned about by Action Fraud - this is about as clear cut as it gets," he said.
"Why do I have to go through the time, cost and stress of doing the work? I have people spending half their week doing this. I'm not being paid by Facebook. It's making the money - if I'm going to have to do that can it pay me a fee to police it?
"It sees each advert as discrete, and the next day there's another one. They're not identical but it's the same thing. They say 'it's a new advert, you've got to report it'.
"It's distressing, and genuinely makes me feel physically sick when I hear someone has lost money because of this, and because they trusted me, and now they blame me. It is very upsetting, personally - not as upsetting as it is for the people who have lost money."
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He said "fake ads" needed to be taken seriously alongside "fake news" as a threat to civil society.
"Our democracy is failing to protect vulnerable from scammers by appeasing one of the world's biggest and richest companies. That is a bit of a threat as well. There isn't enough focus on fake ads."
Solicitor Mark Lewis of Seddons, leading the lawsuit, said: "Facebook is not above the law - it cannot hide outside the UK and think that it is untouchable.
"Exemplary damages are being sought. This means we will ask the court to ensure they are substantial enough that Facebook can't simply see paying out damages as just the 'cost of business' and carry on regardless.
"It needs to be shown that the price of causing misery is very high."
What happens to victims of fraud
A Facebook spokesperson said: “We do not allow adverts which are misleading or false on Facebook and have explained to Martin Lewis that he should report any adverts that infringe his rights and they will be removed.
"We are in direct contact with his team, offering to help and promptly investigating their requests, and only last week confirmed that several adverts and accounts that violated our Advertising Policies had been taken down.”