Suppose you're complaining to your friend Bob about a mutual acquaintance Charlie who deliberately got a girl drunk and then guilt-tripped her into having sex with him. You comment that Charlie violated the girl's consent.
Bob says "Well, actually, that's not what consent means. The law says he can't forcibly rape her and he can't find her unconscious and have sex with her. He didn't do any of those things. So no one's [he does air quotes] 'consent' has been 'violated'."
You would rightly conclude that, although Bob accepts the law about sexual consent, he has very little respect for the principle of sexual consent. Also, that he is a jerk. You might also speculate that he's not a fan of the laws forbidding the more extreme kinds of consent violation, and he might rather those laws didn't exist.
For many principles, there are laws forbidding the most egregious violations of the principle, but there are also social norms, not legally enforced, but voluntarily followed by people who subscribe to the principle. And people who subscribe to the principle are very disapproving of other people breaking those social norms, even if no laws are broken. (For the principle of sexual consent, those norms include not deliberately getting people drunk in order to sleep with them, not guilt-tripping people into sleeping with you, not tricking people into sleeping with you by falsely promising marriage or similar commitment (AFAIK this used to be illegal but no longer is), being very cautious about sleeping with people who are already drunk, etc.) And the principle is the primary, underlying and defining thing: both the laws and the social norms flow from it.
And this is why I object to the way defenders of the principle of free speech get shouted down with "No one's violating your 'freeze peach'! Free speech only means the government can't throw you in jail for your views!" (Even xkcd has got in on this, which surprises me, because Randall Munroe normally seems to be rational and capable of understanding nuance.)
"The government can't throw you in jail for your views" is not what free speech means. It is what the laws about free speech currently say. The principle of free speech says that freedom of speech is a good thing, that it's dangerous for society when it's severely limited, and that people shouldn't live in fear of expressing their views.
And the social norms that flow from this principle are that you shouldn't fire or no-hire people for the views they express off the clock; you shouldn't retract invitations to speakers or lecturers because some activists have complained about their views; you shouldn't doxx people for expressing views you disagree with; and you shouldn't deliberately organise a social boycott of someone because of the opinions they express (if all their friends independently decide to stop associating with them because of their opinions, that's different).
People who accept only the letter of the law and who do not follow those norms (and who sometimes gleefully boast about breaking them) clearly do not respect the principle of free speech, and one might speculate that they would prefer even those limited laws not to exist.