Well he is a confirmed plagiarist. Boston University formed a committee to study his doctoral dissertation and decided he had lifted significant portions of his dissertation from other works. They more or less acknowledged the degree should be revoked but due his being a former person, they said no good would come of it. I wouldn't revoke his PhD either because I wouldn't want to wake up dead after the outcry but yeah, he did steal academically and does not really have a valid PhD. A Civil Rights historian stated that his dissertation "was taken almost entirely from secondary sources." But you can believe if it had been you or me whose dissertation was found to be no better than a high school book report decades after we ceased to exist, our degree would be in the Boston University shredder.
http://en.wikipedia.org/wiki/Martin_Luther_King,_Jr._authorship_issues