
Matthew B. answered 06/19/23
Experienced, patient Harvard Grad
I always look for a transcript when I get a question with a video, and this one supplied the answer to the first question: " They also called a group, actually 19 Hollywood people, who they knew were in the communist party. Now, how did they know these people were in the communist party? Because they had evidence that the FBI had collected and given to them. The FBI had performed a "Black bag job." They had broken into the offices of the communist party in Los Angeles and copied their membership lists. And so they knew exactly who was in the party, and they photocopied people's membership cards and gave those photocopies to the committee."
Looking up "black bag job" in the dictionary, you'll find it involves illegal actions -- it includes searches and wiretaps without warrants. So that's an illegal search, which indicates that the FBI was acting at risk to their own interests. That implies that the threat of communism was strong enough to get the FBI to break the law they were supposed to uphold.
Part 2 is a little harder to answer, but you'll want to consider that many of the Hollywood figures were informing on one another, and that the studios blacklisted the Hollywood Ten when they were indicted for contempt of Congress. People in Hollywood were doubtless afraid for their careers and perhaps more. These were famous public figures and people involved in the most popular entertainments of the day. Hollywood had worked closely with the federal government to create propaganda during WWII, and the studios heads were eager to show they were still aligned with the government and still very patriotic. The public hearings, the celebrities involved and the blacklisting lend support to the idea that the HUAC investigations into Hollywood did add to the atmosphere of paranoia and suspicion in America in the 1950's.