urbanism

It also doesnt account for basic American boredom:

Nearly every time a Boeing fuselage is shipped via train halfway across the country, they have to fix all of the bullet holes in it from bored riflemen in flyover states shooting it as it rolls down the tracks.

Basically the reverse of all of the shooting of Buffalo from trains during the westward expansion.

Eventually, someone with a high powered sniper rifle or even anti materiel rifle would take a pot shot at a vaccuum tube, which would then basically rip itself apart if it penetrated.