It's not a mistake -- people are free to use words any way they want. Also, the "literally" entry over a Merriam-Webster shows Norman Cousins using the word this way:
http://www.merriam-webster.com/dictionary/literally
2 : in effect : virtually <will literally turn the world upside down to combat cruelty or injustice — Norman Cousins>
Language isn't a science, it's an art. This is an example of artistic freedom.
It's not a mistake -- people are free to use words any way they want. Also, the "literally" entry over a Merriam-Webster shows Norman Cousins using the word this way:
http://www.merriam-webster.com/dictionary/literally
2 : in effect : virtually <will literally turn the world upside down to combat cruelty or injustice — Norman Cousins>
Language isn't a science, it's an art. This is an example of artistic freedom.