"Its two headquarters buildings in Rome enjoy extraterritoriality".
The article claims they have no territory, but what they mean is there is no territory capable of supporting a military + institution. I don't know this is a practical counterexample.
Nevertheless, it is interesting to note that clubs and private militaries, and independent autonomous intelligence agencies exist, even if they are on the extreme end of what could be considered a "government".
The catholic church in general is kind of a counterexample in certain aspects, but only because of reasons. The Maltese Order is just one aspect of the general weirdness of the church organisation overall, there are also the separate international legal entities "Holy See" and the Vatican state. Of those three, only the Vatican state actually has any sovereign land area, but of a rather symbolic size. The Vatican also has a kind of citizenship, but it is only awarded for the duration of being part of the churches government. But in all those things you only see shadows and fragments of the past that are in slow and steady dissolution. The dissolution would be far quicker if e.g. Italy were hostile to them, but the opposite is true, probably because of the popular support and gain in international influence for Italy.
The article claims they have no territory, but what they mean is there is no territory capable of supporting a military + institution. I don't know this is a practical counterexample.
Nevertheless, it is interesting to note that clubs and private militaries, and independent autonomous intelligence agencies exist, even if they are on the extreme end of what could be considered a "government".