if $5.6B is protected by your index finger then you're gonna need kidnap insurance, and a really good pair of gloves.
The point is the attacker has to be near you and mot somewhere around the globe
Sigh. I forgot I posted this in a crypto-related thread.
It's not protected by the index finger at all. There is no fingerprint reader in a Yubikey. The only protection is that it requires physical access and can't be triggered from software.