What were some of the main complaints against the effort to identify Communists in the U.S.?

Following the Hiss case, the next major trial of suspected Communist spies involved Julius and Ethel Rosenberg, who were accused of passing secrets concerning America's nuclear weapons program to the USSR. The Rosenberg trial attracted enormous attention both in the U.S. and Europe. The Rosenbergs were convicted in 1951, and executed two years later, despite many protests that they were innocent victims who had been made scapegoats by American anti-Communists.

The U.S. government passed several laws against communism in the 1950s. Critics of these laws objected that they violated the First Amendment to the Constitution, which guaranteed the right of free speech. In 1950, the president signed the Internal Security Act (or McCarran Act), which allowed the government to compile a register of Communist organizations, provided for the internment of Communists in case of national emergency, and prohibited Communists from being employed in defense work. In 1952, the McCarran-Walter Act allowed the government to prohibit Communists and other "subversive" from immigrating to the U.S., and to deport Communists who had immigrated to the U.S., even if they were now American citizens. In 1954, Congress passed the Communist Control Act, which deprived the Communist Party of the rights accorded to other Americans. More than 2,600 government employees were dismissed from their jobs, while more than 4,000 employees resigned rather than submit to an investigation into their political views.