During the period of American neutrality many persons were prosecuted for criminal acts connected with efforts to aid the belligerents. Some of these cases were still pending when the United States declared war on Germany. A very satisfactory standard of success was attained in the ante-bellum prosecutions. Almost before the ink had dried on the proclamation of April 6, 1917, a select company of dangerous Germans were gathered in by the United States Marshals. These prisoners were believed to be potential, and in some cases actual leaders of pro-German plots and propaganda. Subsequent discoveries have quite fully confirmed this belief. Recently a most authoritative document was found to contain among other matters the names of several gentlemen whom the German Government trusted to carry on its work here unofficially after the withdrawal of the official representatives. Of these, all were arrested on April 6, 1917, save one who had already left the country. This disposal of the German leaders had effects which have been continually reflected in the disjointed and sporadic character of hostile outbreaks. One of the most recent, most novel, and most important of the Department’s efforts is the denaturalization of disloyal citizens of foreign origin. Many natives of Germany or Austria, sheltered from summary internment by their acquired citizenship and clever enough to avoid the commission of actual crime, have insulted and injured this government at every opportunity. _Fortunately the naturalization law contains a clause permitting the cancellation of citizenship papers obtained by fraud._ Without waiting for further legislation, which is apparently on the way, the Department has assailed a number of defendants believed to have made fraudulent mental reservations of loyalty to their native countries. Several of these cases have already ended victoriously for the government. More than one defeated defendant has been interned. Meanwhile the summary arrests have continued. From week to week through 1917 their numbers steadily increased. Since about the beginning of 1918, the rate has been more nearly constant. Extremists have advocated the universal internment of alien enemies, somewhat after the English practice. Now, Great Britain interned permanently rather fewer than seventy thousand alien enemies. _The United States would be compelled to intern at least eight hundred thousand Germans and more than twice as many Austrians._ The colossal expense of maintaining this horde in idleness—civilian prisoners of war are far more useless than convicts, because they may not be forced to work—is too obvious to need discussion.