Oh man, let me post quick and get out of the way; I sense some strong opinions will weigh in.
In addition to her outspoken and sometimes "radical" opposition to the war, all I know (and there was some internet mail version of this going around) is there was some sort of incident in which she betrayed the confidence of an American POW on one of her visits to 'Nam. Don't know if this is one of those urban legends or what.
Anyway, I'm outta this one.
Ed