Fair enough, but still, that's not a requirement here, and seems weird and oppressive (indeed my memory is that being required to register where you lived was a classic example of the non-free-ness of the Soviet Union).

> In any case, most people I know always carry their ID card with them in their wallet. You don't need it all that often, but you might as well carry it around, and having government issued proof of your identity is actually quite handy in many situations (situations that are handled with SSID and/or credit card in the US).

Sure, in practice I carry my driving license around most of the time in the UK. But the fact that I don't have to feels important.

Hypothetically, if you owned two houses, and spent exactly 182.5 days per year in each, an outside observer would not be able to tell which one you considered to be your true home. So that observer might presume it is not your home, and prevent you from voting there, or presume that it is, and levy location-based taxes as though it were your full-time residence. Worse, different observers could make those determinations separately, and you might end up paying double taxes while being denied the ability to vote in either place.

There are also concerns about the correct address the government should use to send its official communications to you. It isn't always about knowing exactly where to send the cops in ninja gear to rouse you out of bed at 2 AM.