Yeah he is a doofus, but I think the crime does not really fit the punishment. Prison time isn't going to really help. Do you think he is likely to do this stupid trick again?
IMHO he should get a punishment on the order of what he'd get for a DUI. Maybe 10K in fines, plus perhaps some probation/community service.
I think a 10K fine is a plenty big deterrent for the random idiot, and half a million is not enough of a deterrent to stop a real terrorist.