James Ball, author of Post-Truth: How Bullshit Conquered The World, commissioner of the London School of Economics' Truth, Trust and Technology report, and journalist covering online and Russian disinformation, surveys the landscape almost three years after "fake news" became the word of the year.

From Facebook's efforts to tackle "dark ads" to state responses to Russian interference, from automated fact-checking to new rules for online information – lots has been tried and is being tried. But what works (and what doesn't)? And are our priorities in the right place?