Such reports as the German agents at fixed posts have to make to their employers are communicated, whenever possible, by means of the travelling inspectors, for the postal service is not to be trusted where espionage is concerned. During the French Revolution there was originated what was known as the "Cabinet Noir," or secret service of the post office in France, of which the duties were to intercept, open, and where desirable destroy or replace, such letters as were deemed unfit to reach their senders, in the best interests of the State. Berlin, with its genius for developing other people's inventions, adopted this idea, and made of it one of the regular weapons of the secret service. It operates not only internally, but also internationally, and any suspected letters are freely opened and read; sometimes they are suppressed altogether from their recipients; sometimes false letters, giving contrary instructions, are substituted, and suspected spies of other Powers are caught by this means. The idea has been generally adopted by most countries; but, in practically any country but Germany, the idea of personal and national honour is sufficiently strong to keep absolutely secret the doings behind official doors. For instance, at the trial of the spy Ernst at Bow Street, it came as a surprise to many people to learn that the British postal authorities possessed powers under which they might open any suspected missives, with a view to ascertaining their contents when deemed essential for the safety and well-being of the State. It is common knowledge in Germany that no letter is safe from being opened, and the powers which the British post offices exercise only in case of genuine suspicion are utilised in Germany to a far greater extent. Further, the officials at the Berlin post office "Cabinet Noir" do not always maintain the absolute secrecy that their work demands, and sometimes there creep out details of other things as well as espionage. Apparently, every German official has his price in his own country, and the habit of spying is so ingrained in the race that commercial secrets are bought and sold not only in the interests of German firms as a whole, but in the interests of one rival German firm which desires to steal a market from another firm of Teutonic name and standing. It appears that Stieber, by organising his colossal system of espionage, laid the foundations of national pettiness and deceit--the German character as a whole has been undermined by the knowledge that nobody is safe from espionage, and all acts are liable to be reported, while blackmail is a flourishing industry.