Which term do you use when discussing immigration: "illegal," "undocumented" or "unauthorized"?

[Sikeliot]

I almost always say "unauthorized" because I believe it is the most politically neutral, does not obscure the reality of the situation, and neither sounds inhumane nor inaccurate. It implies exactly what it sounds like: the person has not received authorization by the government to enter the country.

I sometimes will say "non-citizen" but this also does not differentiate between people with and without residency (i.e. Visa, green card, etc) so it is not the most accurate.

"Illegal immigrant" sounds as if the person immigrating, rather than the action of immigrating through improper channels, is illegal. No human being by virtue of existing, is illegal. Even worse is "illegal alien."

"Undocumented immigrant" shifts responsibility off the immigrant for arriving through improper channels and makes it sound as if there was a simple clerical mistake, that is the government carelessly neglected to issue documentation where it should have been issued. This obscures the reality of what is occurring.

[gıulıoımpa]

No human being by virtue of existing, is illegal. ."

i don't judge people for what they are or what they look like, i judge the for the choiches they do.

[KMack]

Illegal Alien/Immigrant.

[Eugene Finkelstein]

As a Russophone post-Soviet Jewish atheist with Ukrainian citizenship, Polish roots and Cambodian residency, I prefer to use term "funny".
But actually, if somewhat modernized, your propositions could easily fit too: "illegal human being", "undocumented brain", "unauthorized soul"...

[Marinus]

I use the term illegal.

[Catarinense1998]

Son of prostitute or motherfucker.

[idioteque]

"Illegal".

If they are here not legally, they are illegal.

[de Burgh II]

Illegal non-citizen.

[Smaug]

Illegal. No need to overcomplicate things.

[Newsboy]

I can see where you are coming from Sike, but still I prefer the term 'illegal'.