The problem of "fake news" is the same as the age old Koan of truth vs. falsehood. Truth is subjective and relative to the time period and cultural mythologies, and is always changing. How can we even begin to solve this apparent problem if we can't even objectively define our variables, lest we become digital Don Quixotes?
"1 + 1 = 2" is true and objective for an infinite time period.
However, "Truth" in the sociological sense is not constrained to mathematics.