This is golden for men who want to ditch their families, or other criminals looking to escape punishment and find new targets.
On the other hand, it could also be a refuge for people who had made an injudicious choice and have had second, wiser, thoughts. It might be easier to reform in a place where nobody knows your name (maybe).
One of my wife's ancestors was apprenticed, in what's now Germany, to an abusive master. The lad, pushed too far, rammed the master into a horse-trough and took a boat to the USA to avoid the harsh penalties inflicted on insubordinate apprentices.
My cousin's geneological research suggests that a not-too-distant ancestor of ours was not born with the name he died with.
The option of "starting over" is an alluring one. Part of the legend of the French Foreign Legion was that you could join under an assumed name, and earn the new name and a new life in the Legion. They actually did some background checks--at least some of the time.. A stint in the Legion would "pay for" your crime--at least in the great myth of the Legion.
Suppose you're not a crook looking for new victims.
Maybe you have some obligations that would make "declaring my old life bankrupt" a grave offense. Then running away is obviously evil. Or perhaps you're a teenage who thinks home is horrible and you'd be ever so much better treated in the big city. Maybe you're right, but more likely you're a fool who is about to find out what predation means. But maybe the environment really is oppressive and unjust, and the whole community's disapproving eyes are on you, and you need to get out from under them. Probably you won't ever cut and run, but I think I understand the appeal of having the option.
Having a national ID makes this escape a lot harder. You can easily understand the appeal of having such a thing--it makes catching deadbeat dads (and moms) easier, and makes it easy to tell who is a citizen entitled to benefits and who is not. And, in case of war, it makes it easier to spot enemy infiltrators. (We're at war now and probably will be for the rest of my lifetime. Lots of wars have taken decades or centuries--the Spanish Reconquista took 500 years.)
But a universal ID lets the powers-that-be apply the small-town's lack of privacy without any sense of small-town community. If you're the wrong flavor of citizen, the nation's disapproving eyes are on you, without any mitigation or any escape or possibility of starting over. China is our current bad example--it maintains a database of all its residents with the possibility, and already the beginnings, of a system to track everyone and punish the smallest deviations from the will of the powers-that-be.
One of the prices of liberty is insecurity. It shouldn't be easy to duck and run, but it seems to me that it should be possible. For criminals with connections, it always will be.