You are correct the line is in Mexico and CBP has no jurisdiction, but they can still dick with the perps once they are in US soil.
I had a guy cutting in ahead of me inside the building. I told him to get back in line or I would call CBP. The woman CBP heard the exchange and sternly ordered the guy back and start over at the beginning of the line hehe.
Doing something is better than just shutting up and take the abuses.
