US President, Donald Trump, has used his address to the UN General Assembly in New York to blast social media companies for what he said was an attempt to “silence the voices of the people.”

“Even in free nations, we see alarming signs and new challenges to liberty,” Mr Trump said. “A small number of social media platforms are acquiring immense power, over what we can see and over what we are allowed to say.”

Conservative groups, such as Prager University and Live Action, have increasingly expressed concern hat social media companies are now working to shadow-ban or openly suppress their message, after initial successes on growing networks and communities on these platforms.

The US President described the issues raised by these big tech companies as: “A faceless bureaucracy operates in secret and weakens democratic rule. Media and academic institutions push flat-out assaults on our histories, traditions and values,”

He affirmed that his administration had made it clear to social media giants that freedom of speech was paramount.

“A free society cannot allow social media giants to silence the voices of the people,” Mr Trump told world leaders. “And a free people must never, ever be enlisted in the cause of silencing, cancelling or blacklisting their own neighbours.”

Bloomberg reported that his remarks had an immediate effect on the stock market value of the biggest tech companies:

U.S. President Donald Trump’s address to the United Nations General Assembly helped knock $56 billion off the value of some of the biggest technology companies.

The combined market cap of FAANG stocks — made up of Facebook Inc., Amazon.com Inc., Apple Inc., Netflix Inc., and Google parent Alphabet Inc. — tumbled after Trump made negative remarks about the growing power of social media platforms, a signal to some investors that the industry could soon face extra scrutiny from federal antitrust regulators.

“It’s a reminder that this is a risk they’ve never had before and you have to take that into account from a valuation standpoint,” said Tom Essaye, a former Merrill Lynch trader who founded “The Sevens Report” newsletter. “The president has a belief that social media companies are extremely powerful and not particularly favorable to his policies or potentially his point of view.”