I wonder if biometry (e.g. a fingerprint) could be reliably used as the private key (and thus the identity on the blockchain). That is, without a 3rd party / ex

I wonder if biometry (e.g. a fingerprint) could be reliably used as the private key (and thus the identity on the blockchain). That is, without a 3rd party / external system. For trust, the network (as any blockchain network) would have to be properly decentralized, and (good or at least benevolent) people would have to be incentivized to run the network. I.e. there would be a monetary value (a coin, or a token), which would have its own pros and cons as seen by various parties. (Mentioning fingerprints, I cannot but reference the movie Southland Tales, which in my view was the most prophetic movie ever made.)