We are at a time in human history when our lives (and minds) are being shaped by technologies most of us hardly understand, mis- and dis-information have proven to be powerful tools wielded to influence how we think, vote, spend our money and time, and even what we believe about our fellow citizens. Social division fueled by extreme emotion has proven dangerous and even deadly. Learning how to think critically about all this can protect us from the self-service influence of others, and from our own biases, prejudices, and misunderstandings of reality.
Furthermore, our attention is a precious commodity, and some will do almost anything to get it (and make money in the process). Commercial, political, and social forces are working to persuade and influence us, sometimes in ways that undermine personal and social well-being. There are deep divides in American culture that effect all of us one way or another. Your ability to think critically about all of this in a hyper-mediated world may be one of the best ways to defend to yourself intellectually and emotionally, and make balanced, rational decisions.
Mis-information and dis-information are both false. The difference is intent. Mis-information is false information spread by people who don't know it's false and don't intend to deceive others. Dis-information, on the other hand, is spread with the intent to deceive. False information has always been part of human communication, but in the twenty-first century we have technologies that allow for increasingly sophisticated forms of false information that can be distributed widely and instantly.