A DNA lab company could potentially act as a third-party administration to identify users on the blockchain, by assigning a unique number to their DNA Sequence, the unique identifier (not the actual DNA sequence) could provide proof of personhood, the theory being that a meat bag submitted their saliva to be tested in the first place, their submission would need to be documented by going to the lab in person and of course, there will be cameras watching....this idea I'm presenting is just a fleeting thought...