The text summarizes the events surrounding the case of Julius and Ethel Rosenberg, who were convicted and executed for conspiring to steal atomic secrets for the Soviet Union in the 1950s. The case was made possible by the testimony of David Greenglass, the brother-in-law of the Rosenbergs who was already a Soviet spy. Senator Joseph McCarthy also played a role in identifying and punishing suspected communists and Soviet spies during this time. Greenglass served 10 years in prison for his involvement in the plot. The Greenglasses were known to be ardent Communists and David testified against his brother-in-law and sister-in-law in the trial. The prosecution's case heavily relied on Greenglass's testimony.