The Fourth Amendment prohibits the government from conducting searches of “persons, houses, papers and effects” absent the imprimatur of a warrant from a judge. Does this protection extend to the veins in your arms and the blood within?
One would hope so. It is hard to imagine many acts more intrusive and intimate than the drawing of blood. It is bad enough when done by your own doctor or a nurse, but should the state be able to do it without advance judicial permission?