Public inquiries have been an important clearing house in the battle for truth. They’ve settled arguments about who was responsible for national scandals and tragedies and, crucially, taken the pen away from people in power and given it to victims and campaigners. In the age of social media, when anyone can hold the pen, can the idea of the public inquiry survive?

In theory, it’s the crucible where politicians encounter journalists and a story is revealed in the white heat of the moment. In practice, critics would have it, it’s a cooked-up charade co-produced by the media and politics. What role does the political press conference have now in the battle for truth?

In the court of public opinion, Facebook is Exhibit A in the battle for truth; the most powerful example on the planet of the damage unregulated social media is doing to the public square. Facebook’s response has been to set up a higher court, its own supreme court in fact. Whatever it does, whatever it says, it won’t be the last word.