Mark my words: When the time comes for the 2012 year-end lists, this story will be among the "Biggest Social Media Fails" for the year.

If you haven't already heard, McDonald's is the latest poster child for social media gone awry. What started out as a simple Twitter promotion campaign—and then evolved into an effort to encourage people to talk about their favorite McDonald's stories—turned into a case of "tweetjacking" of the worst kind.

By Hollis Thomases as seen in Inc.