This work by major publishers is now beginning to turn back the tide of fake news.
News groups, such as 20 Minutes, Libération, Le Monde and FranceTV, get thousands of requests a month to sort out real news from fake.
A new election law will mean the origin of all information has to be revealed on social media.
Claims of lies about Trump and Brexit plus a spike in false gilet jaune stories prompted the law but news groups have already been fighting against fake news, or infox in French.
It is having an effect. Romain Badouard, communications lecturer at Panthéon-Assas University Paris II, said: “Studies have shown there is less and less fake news because of all the attention it has been given in the last months.
“Social media plays a big role by deleting them too.”
Last year, Facebook deleted 500million accounts. Along with Twitter, it has removed accounts, pages and groups for publishing “influenced” content for the UK, US, South America and Middle East.
Researchers from Michigan, Princeton and Exeter universities have found fake news falling since 2016, with social media users engaging less with unreliable sources – although older people are still most likely to share false stories.
Mr Badouard said: “The new fact-checking services are a great initiative.” But “people who share fake news will not look at them. These people do not trust the media and tend to go on alternative websites influenced by a certain ideology”.
Facebook also helps fund fact- checking at 20 Minutes’ Fake Off, Libération’s CheckNews and Les Décodeurs at Le Monde, but the groups already made their own checks.
Les Décodeurs does not directly reply to questions but prepares topics according to the news. It also offers a “décodex” database where you type in a website and, if it is known, it says if it is politically-oriented.
Samuel Laurent, editor-in-chief, said: “We must pay close attention to what is going on and look at people’s reactions.”
CheckNews at Libération is a search engine where you type in your search or submit your own topics for consideration. It has had 16,000 requests for checks since launching in 2017.
Journalist Fabien Leboucq said: “We have replied to 2,700 questions so far but there are peaks of questions sometimes – as with the Benalla affair and gilets jaunes events.”
Under the new law, anyone can ask a judge to stop false stories being spread in the three months before an election. The CSA broadcasting watchdog can also suspend TV channels influenced by foreign powers.
President Macron is a leading backer of the law. He was falsely accused of having a hidden Bahamas bank account during his 2017 campaign.
Nearly nine out of 10 French people think fake news is an important issue and four in five back the “anti-fake news law”, according to a France Info poll.