Social media: More powerful than government?

After social media suspended Donald Trump, some have questioned the power of the Silicon Valley giants: Alexei Navalny and Angela Merkel, among others, have wondered whether it was a step too far. The big five of Facebook, Amazon, Apple, Google and Twitter may have had humble origins but they're now among the biggest companies in the world, wielding enormous global influence. Has big tech gone too far, with this kind of censorship removing more content and threatening freedom of speech, or is it long overdue? And in the age of these new media monoliths, do we want them to be mere platforms or must they accept that they're publishers, responsible for content and democratically accountable?