5. Under anarcho-capitalism, all airports, roads etc. are privately owned, and the owners have the right to arbitrarily decide who can use them and who can’t. Most owners would probably exclude habitual criminals.
It isn’t easy to decide how public property ought to be managed while it’s still (unjustly) “owned” by the state. Rothbard (in his last years) and Hoppe think the state ought to manage it’s “property” the way it would probably be managed by it’s rightful owners (the net tax payers); this should preferably be done at the local level. This means that local governments ought to be able to exclude criminal immigrants. In addition to the article Sons of Liberty linked to, see “What To Do Until Privatization Comes” by Rothbard (here) and this short argument by Stephan Kinsella against open borders. See also this article by Hoppe against free immigration and this article by Hoppe on privatization.