The question is how do you define false information. Do we rely on consensus ? For e.g. let's say majority of the world population believe that earth is flat.

The question is how do you define false information. Do we rely on consensus ? For e.g. let's say majority of the world population believe that earth is flat. In that case, will that still be false information? Even if we go with consensus, it's such a difficult problem to solve in this age of internet where new content is created at such a rapid pace.