In the 1960s, the East German foreign intelligence service HVA issued this tiny camera, which takes photos of documents and uses a chemical process to shrink the text down so that a block of text appears no bigger than a period. This way agents could hide secret messages in plain sight. Boghardt points to an infamous incident involving microdots: Dusko Popov, a double agent during World War II, gave microdots to the FBI that mentioned German interest in Pearl Harbor. FBI director J. Edgar Hoover didn't trust Popov, however, so he never passed the information to president Franklin D. Roosevelt.