[throwaway613834]

> Is this something that actually happens nowadays?

Yes, I personally know someone this has happened to. Also resulted in my own personal name/address/other info (amongst that of many others) also being demanded and hence provided to the government.

> Why on earth would anyone ever consent to this nonsense?

What would you do if you weren't a citizen and had a family to come back home to? Just be okay with being denied entry?