Personally, I'm not really comfortable with the existence of a database of people from which to compare faces against.
However, I think it's perhaps more worrying that one day this evidence will be presented in court and the jury will trust the accuracy of "AI" over their own judgment.
To clarify, the situation I'm thinking of is where a grainy CCTV image is shown to the jury. The AI expert comes in and talks about all of the technical details of their algorithm and how it determines that the grainy image is of defendant A with 96% probably.