You do admit that this is really just a theoretical exercise.
It would be interesting to see if you could print one out from home and also a "real" one from the airport to see what happens when you try to scan it. (not that i'm advocating doing anything potentially illegal)
I would think that they would have thought of something as simple as reverse engineering a string of characters in a barcode and put security measures in place to prevent (or at least make more difficult) potential hacking.