This link was sent to me by Erin... via iPhone. That's right, you can send me links even when you aren't sitting in front of your computer like a dork. Learn from Erin's example.
History has presented us with numerous cases, from different parts of the world, where a corpse has been ritually "killed" a second time. Because... people are dumb?
Some of these cases are understandable, like Vlad the Imapler, "who was beheaded following his assassination." You don't want to make a mistake and have that guy coming after you because you didn't kill him properly. Or Gerard Butler, who was beheaded and crucified after he died at the end of that movie. They were pretty grumpy with him, boy howdy, and desecrating a corpse can be a good method of working out those issues.
Some of them, however, are just ridiculous. "John Wycliffe (1328–1384), was burned as a heretic 45 years after he died." Why? This was the 14th century, nobody lived past 18! Nobody! Why would you get mad enough at some guy who was talking smack about Jesus to your grandfather to dig up and burn his corpse? There weren't any other live heretics running around to burn? Or at least more recently deceased heretics? I am so glad that I have Twitter to distract me from doing stupid crap like this.
There's also the dramatic example of Oliver Cromwell, whose corpse was exhumed, then hanged, drawn and quartered, and tossed into a pit sans head. His head was later given a burial in 1960. Lesson learned: don't try to kill your monarch. This also leads us to one of the best out-of-context sentences on the Wik: "See also Oliver Cromwell's head." He's so historically relevant, his dismembered body part has its own Wikipedia article!