Labeling Julius and Ethel Rosenberg a "crime" duo is still a matter of debate. The two were the first civilians in United States history to be executed for conspiracy to commit espionage in 1953. Charged with allegedly sharing information about the atomic bomb with the Soviet Union, their death sentences prompted massive public outcry. "Do not let this crime against humanity take place," Pablo Picasso urged authorities. And Jean Paul Sartre wrote "you are afraid of the shadow of your own bomb." Even Pope Pius XII requested a pardon for the couple from President Eisenhower, to no avail. Guilty or not, the Rosenbergs died in the electric chair at Sing Sing prison, two years after the Lonely Hearts Killers met the same fate.