McCarthyism was about prosecuting communists and socialists which is something that the government had no problems with. They didn't care who got caught as long as there were no communists to usurp the government or motivate the people to overthrow it since there was a big scare about communism becoming powerful.
The result was that a huge amount, the majority of people questioned, were questioned and punished while being completely innocent as it all turned out to be a contemporary witch hunt. Those blacklisted couldn't find jobs or places to live at or anything similar because the people believed McCarthy when he spoke about who a communist was.