Do you fear being buried alive? Back in the eighteenth century, people were very concerned over the idea of being buried alive in coffins when they weren't necessarily, officially, positively, DEAD. In fact, many people were buried alive after falling into comas as a result from cholera. It became such a concern that "Safety Coffins" were invented. This article from io9.com talks about the invention of safety coffins for those who feared waking up to find themselves Six Feet Under. Some went so far as to make sure that they were buried with food, "in case they needed a snack before breaking out."
Apparently, nowadays people are more concerned with being off the grid than starving to death if they're buried alive. Now you can buy a coffin-ready PC to make sure you can stay connected. The article has a photo of one installed in a coffin.
I'd certainly like to read the Facebook status written by that person when they wake up.
Thanks to Barry for the tip.