What methods did Stalin use for controlling opposition?

Stalin had a variety of methods available to him to control opposition from all parts of the Soviet Union. Stalin made use of Soviet secret police to gather information on Communist Party members who were potential threats to his power. There were no "free" elections in the USSR, only elections for Communist Party members or policies supported by Stalin's version of Soviet communism. He also controlled the mass media. Radio, TV and newspapers were all communist controlled. In this manner the majority of common Soviet citizens, had little means of knowing about the events in the USSR and events in the world, except via government controlled media.

Stalin was the dictator of the USSR for a long period of time. Roughly from the late 1920's to his death in March of 1953, the USSR was under his control. He was able through all means at his disposal to use fear as a method of keeping any opposition at bay. His courts of law sentenced communists to death or long imprisonments in Siberia.

Surprisingly, Stalin was able to fool many of his closest allies in the Party. There came a time however, when this was no longer possible. In Nikita Khrushchev's writings after the death of Stalin he made this remark was is paraphrased: It came to be a mystery to us ( meaning the people within Nikita's close network of allies ) that without exception, all communists brought to trial for various crimes, were always convicted."