If I remember correctly Joseph Rutherford got put in prison because of the Finished Mystery. A book that explained every verse of the Bible prophecies of Revelation and Ezekiel. By1920 he had been released and was helpfully explaining that the world had legally ended.
Without any cost, absolutely free for $6.50 (you are just paying for the handling and paper cost (at a bargain wholesale rate)) he was now distributing Studies in the Scriptures. With them, your Bible would become a new book to you. Hmm wonder what the title was?
Just a stab in the dark, maybe Russia still understands the concept of blasphemy and suspects it can negatively impact the population.
Communication becomes tricky when you mess with semantics.