Fixed fortifications are monuments to stupidity quoth Geo. Patton. There are many kinds of fixed fortifications and not all are used in war of the conventional sort. Here's an article in Reason describing the various sorts of fortifications ranging from national borders to prison walls, to statute law and some of the methods used to circumvent them.
Smuggling Maple Syrup out of Quebec? Who knew? Digital smuggling? Sure. Don't smuggle a gun, post the 3D model on the internet and let anyone with a CNC milling machine make his own from scratch. Yee-Haw, as they say.