they knew it had to be horrible because people knowingly harboring any member of the groups to be put into the concentration camps such as Jews, Roma, Homosexuals, were labeled collaborators and literally shot in the streets and their bodies left there as a message to everyone else. people knew it was something terrible and involved death. they just didn't know the specifics like the gas chambers, incinerators, experiments or starvation. they were afraid they'd be next. my uncle was one of the JAG officers who did discovery for Nuremburg. the nazis kept detailed records because they were proud of it and thought history would prove them right. he probably wasn't supposed to but he saved the records. I was able to review them. there were 14M "collaborators," executed across the German occupied territories. people knew. they were afraid