Prime Minister Theresa May has been told that her pledge to increase internet regulation, in the wake of the London attacks, will not work.
Mrs May said that technology firms were providing a “safe space” for extremist views, and as such areas of the internet must be closed for national safety.
Mrs May said: “We cannot allow this ideology the safe space it needs to breed.
“Yet that is precisely what the internet, and the big companies… provide.”
However, Facebook, Google and Twitter have defended themselves, saying that they were investing a large amount of resources in this area.
Culture Secretary Karen Bradley praised the action that social media companies have taken in response to indecent images of children.
“We now need to see the same response in terms of extremism and radicalisation. We know it can be done and we know the internet companies want to do it,” she told the BBC.
Home Secretary Amber Rudd said that tech companies must be working harder to remove extremist content and believes there should be a limit on the amount of end-to-end encryption available to terrorists.
End-to-end encryption means that any intercepted messages would be unreadable, meaning that information is kept secret from authorities.
In response, the largest social media networks have been highlighting their efforts to crack down on terrorist activities.
Google emphasised that it had already spent hundreds of millions of pounds in its fight to prevent abuse on its platforms and has been working on an “international forum to accelerate and strengthen our existing work in this area”.
The firm added that it shared “the government’s commitment to ensuring terrorists do not have a voice online”.
Facebook said: “Using a combination of technology and human review, we work aggressively to remove terrorist content from our platform as soon as we become aware of it – and if we become aware of an emergency involving imminent harm to someone’s safety, we notify law enforcement.”
Meanwhile, Twitter said “terrorist content has no place on” its platform.
“We continue to expand the use of technology as part of a systematic approach to removing this type of content,” the firm added.
The Open Rights Group, which routinely campaigns for online privacy and free speech, issued a warning saying that increased internet regulations would push terrorists towards “vile networks… in the darker corners of the web”.
“The internet and companies like Facebook are not the cause of hate and violence, but tools that can be abused.
“While governments and companies should take sensible measures to stop abuse, attempts to control the internet is not the simple solution that Theresa May is claiming,” Open Rights said.
Director of the International Centre for the Study of Radicalisation, Professor Peter Neumann, was critical of the plans.
He wrote on Twitter: “Big social media platforms have cracked down on jihadist accounts, with result that most jihadists are now using end-to-end encrypted messenger platforms e.g. Telegram.
“This has not solved problem, just made it different… moreover, few people (are) radicalised exclusively online. Blaming social media platforms is politically convenient but intellectually lazy.”