I wish I could detail it, but this is a public forum. I will say that the formatting method is also used by hospitals and large corporations to Scrub disks when they have reached end of life. The Wikipedia dump is simply a chunk of data about equal to the amount of RAM that the machine has. As for the dead man's switch, it isn't physical. There are a list of events that can trigger it and I have done my best to ensure that the list includes any possible attempt to access the machine by anyone other than myself. It also helps that the data on the machine would not be a terrible loss to me if the switch were accidentally triggered.