A browser plug-in that dynamically inserts a snippet of warning text before any news article that reminds you that it’s the media’s job to make the world’s problems your problems.
It's easy for your day to get ruined by dramatic headlines about the world burning down around you (even though your day-to-day life will rarely feel the effects of it) so it's good to be reminded that you don't have to worry about that which you cannot change.