A Swedish national was deported from Denmark today. This is a very extraordinary case, since citizens of Nordic countries are usually free to travel without any documents within the Nordic Passport Union, as well as within Schengen (with documents).
If he wish to travel out of Sweden, there is a significant possibility that he will need to have a stopover in Denmark, or at the very least fly over Danish airspace.
The specifics of his deportation is not known, other than that he will no longer be allowed to enter Denmark. Generally speaking, how big of a problem will this pose?
Will he be allowed to fly over Denmark? Will he be allowed to have a stopover in Denmark, as long as he doesn't leave the international terminal? I assume it will work much like when you transit through a country in which you don't have a visa.
Of course, practically speaking, since a flight within the Nordic countries is almost considered a domestic flight (no passport checks), it will be hard to regulate, but let's work from the assumption that he will not enter Denmark unlawfully.