It's not quite the same. I assume you mean donated blood, because otherwise your response doesn't make much sense. So if you are cut, and leave blood behind (yo

It's not quite the same. I assume you mean donated blood, because otherwise your response doesn't make much sense. So if you are cut, and leave blood behind (yours and the donated blood?) The could be used to convict you because it's something you abandoned. Where in this case, the got a court order to take information from a device. Not to compare it to a sample they already had, but at a single point of evidence, that will be used to incriminate. Additionally, that same evidence could be used to prove innocence, where the pacemaker data couldn't be used as evidence to prove innocence. EDIT, Also, the 4th is protection from unreasonable searches... e.g. if the device I required to live needs extra data to do it's job. IMO, it is an unreasonable search to use that against me because I have no choice in wither or not, I create the data, or use the device. Because the alternative is I choose to die.