I'd hate to point this out, but requiring that would mean you're intentionally violating the US constitution. Wearing a veil is a part of their religion, therefore it is perfectly acceptable under law. A good thing? Probably not, but change the constitution if you so fully believe that it's wrong that someone's religion would interfere with a photograph.

Another thing, you saw these pictures are used to determine who you are, but if a person is wearing a veil all the time anyways, you can't just spot them walking down the street, you'd have to stop them specifically.