it would be handled in the normal customs line. They would almost certainly give a warning for something like that. But with Global Entry it's different - you go through all the steps, fingerprinting, background checks, and interviews to become a known traveler to show that you are not a risk for violating customs law, and in exchange you get favorable treatment and less stringent screening at customs. But if you are found to be in violation after all of that, the penalty needs to be more severe. You can't say that weren't aware because you agreed to those standards when you signed up for GE, and if they chose not to enforce those standards, it's going to make it harder for everybody else who has GE.