A new pledge to stop hateful content from appearing online will have a significant impact on how social networks operate, according to Maurice Levy, chair of one of the world's largest ad groups.
The so-called "Christchurch Call" aims to sign up countries and tech companies to a pledge to clamp down on hate content after shootings at two mosques in Christchurch, New Zealand, were broadcast live on Facebook in March.
Speaking to CNBC's Karen Tso at the VivaTech conference in Paris on Thursday, Levy, chair of advertising group Publicis, said: "(New Zealand) Prime Minister Jacinda Ardern … (made) a very moving speech regarding how the hatred and speech of hate are contaminating the social network(s), and I believe that this is a landmark in how people will now operate and how some discussions will be quickly erased from the social networks."
On Wednesday, Ardern and French President Emmanuel Macron announced plans to stop hateful content from appearing on sites such as Facebook, YouTube and Twitter.
Asked whether the measures go far enough, Levy said: "It's not only a question of technology, it's also a question of willingness and there was a big debate regarding freedom of speech and can they remove things because of the freedom of speech or should they have a kind of censorship? At the end of the day there is a balance which has been made and I think that where we are today is a good step."
Among attendees at Wednesday's meeting at the Elysee Palace in Paris were Twitter CEO Jack Dorsey, Microsoft President Brad Smith, representatives from Facebook and Google, as well as British Prime Minister Theresa May and Canadian Prime Minister Justin Trudeau.
Facebook CEO Mark Zuckerberg did not join but had already met with France's Macron last week.