Sarcasm is the protest of people who are weak.

-- Gene Forrester in A Separate Peace by John Knowles

The point, I think, is an important one. Sarcasm is often used to deride or belittle a person or an idea euphemistically. Sometimes the speaker avoids plain-spoken criticism to soften the blow, or for fear of reprisal. Sometimes sarcasm poses as a shorthand to mask vagueness, handwaving, or unformed thoughts.

Sarcasm is what's wrong with the kids today. It is ripping apart the fabric of society. Okay seriously...