no
If he is a frum yid, and is in the business for a while, I don't see why not.
People should stop people so selfish. When broker is up to lose $1000, and sometimes $10,000 (if ticket cannot be re-booked) and it can be resolved with a simple fax of an ID, it is absolute selfishness to deny that, simply because you can.
Most brokers are in a for a while, and if they really wanted to be in the identity theft business, they don't have to start with you.
And besides, what can one do with a copy of a passport?