How to check real or fake news and avoid their serious damages, consequences

The world, Governments and especially Tech companies who are directly struggling to combat fake and false news, disinformation, don't know that there is one special kind of mass killing that is really worse than the above mass shootings. No gun, no bullets, but it can kill millions of people quietly and hiddenly. What is it?

The biggest Tech companies in the world Facebook, Google, Twitter, Amazon and Governments of many countries have been incapable of solving this problem of fake news. So, how can disinformation, fake news be solved to the every roots successfully?