By far the larger number of persons of German descent living in Australia were loyal to the flag under which they lived, and where this was clearly the case, the disposition of the military authorities and their useful police allies was not to molest them. Immediately after the outbreak of war there was a rush of applications for naturalisation, which was granted generally without any searching inquiry into the bona fides and loyalty of the applicant and without the military authorities being consulted. Later in the war careful enquiries were made as to all persons likely to be disaffected, and all persons born in enemy countries were required to report themselves and be registered. It may confidently be said that no persons of this class who acted and spoke with discretion suffered annoyance by official direction, however much they may have been vexed by their neighbours or eyed askance by former friends. But some Germans were boastful and aggressive. They loudly proclaimed that victory for the Central Powers was inevitable, and made no secret of their disposition. In Sydney, for instance, it was reported that many members of German firms, wool-buyers, island traders, and shippers. showed that they could not be trusted. The military authorities were not inclined to take any risks with such persons. Again, in Melbourne, after the German Club in Alfred Place, Collins-street, was closed, some of its former members who had been in the habit of meeting there nightly to gossip over beer and tobacco, continued their convivial fraternising at a cafe kept by one of their compatriots. They were to be seen emerging therefrom in the early hours of the morning. Perhaps they had not been plotting treason, or even discussing politics ; they were capable of wrangling about the categorical imperative of Kant, or the construction of a Beethoven symphony. Some of them were well known to the Melbourne public; one was a musician of some distinction, whose friends warned him that he was running grave risks. But the advice was unheeded. The police became suspicious about this knot of enemy subjects who were to be seen emerging by a side door on dark nights. The result was that the entire group was suddenly consigned to a concentration camp [sic] to meditate upon its folly.
From The Official History of Australia in the War of 1914-1918, Chapter IV "The Enemy Within the Gates" (Ernest Scott, 1941).