One of the many things Salvian mentions that is starting to be more common in the U.S., but was unheard of just a few years ago is people fleeing the Empire and renouncing their citizenship.
"Thus, far and wide, they migrate either to the Goths or to the Bagaudae, or to other barbarians everywhere in power; yet they do not repent of having migrated. They prefer to live as freemen under an outward form of captivity, than as captives under the appearance of liberty. Therefore, the name of Roman citizens, at one time not only greatly valued, but dearly bought, is now repudiated and fled from, and it is almost considered not only base, but even deserving of abhorrence."(pg.136)
Early roman expats: http://iPerpetualTraveler.com