British Prime Minister Theresa May has called on technology investors to help social networks stop providing a platform for terrorism, extremism and child abuse.

Speaking at the World Economic Forum (WEF) in Davos, Switzerland, on Thursday, May said tech companies such as Twitter and Facebook needed to take their responsibilities to society more seriously.

“No one wants to be known as the terrorist platform or the first choice app for pedophiles,” she said.

May also argued that investors have a part to play in the direction of social media companies.

“Earlier this month, a group of shareholders demanded that Facebook and Twitter disclose more information about sexual harassment, fake news, hate speech and other forms of abuse that take place on the companies’ platforms,” she said.

“Investors can make a big difference here by ensuring trust and safety issues are being properly considered. And I urge them to do so.”

May noted that at least one new artificial intelligence (AI) company had opened in Britain every week for the past three years. She also warned against the misuse of AI, however, and said the U.K. would be joining WEF’s new council on artificial intelligence in order to help shape regulation.

The prime minister said a post-Brexit Britain would remain a good place to set up a digital business, arguing that technological progress is “fundamental to the advance of humanity.”