If you've seen The Lord of the Rings, you know Denethor - he's the grey-haired steward of Gondor who gives in to despair and tries to burn himself and his son Faramir after thinking that defeat is inevitable.
What the movie doesn't reveal is why he gave into despair. In the books, Denethor was originally a wise, brave, noble leader. However, he craved information and used a palantír to get it. A palantír is a kind of crystal ball that reveals far-off and future events; while it cannot lie, it can manipulate by showing events out-of-context.
Denethor became obsessed with his palantír, thinking it gave him knowledge about the world. However, it selectively showed him worse and worse events. He saw the armies of Mordor growing stronger and closer every day, but he did not see the reawakening of Theoden or the courage of Frodo and Sam. And when the enemy was at his gates, the palantír showed him a fleet of menacing ships approaching from the south, neglecting to reveal they had been commandeered by his allies and were coming to his rescue. His false view of reality led Denethor to despair and ultimately to suicide.
I see similar things happening today, including to myself. Often our craving for information (or simply for more content) leads us to a skewed view of reality, which results in despair and feelings of hopelessness. Often the news we read or the websites we browse are biased in favor of pessimism. It's wise to remember this, and focus on the positive things that you can control, rather than obsessing over the negative things you cannot. Don't make the same mistake Denethor made.