You would have to sue over a right or over actual damages that can be proven. There is no right to speak with people, people are allowed to chose to speak with whoever they want from a legal point of view.
How about using the DF'n someone to chill his free speech to warn his loved ones about a cruel fraud being perpetrated on them by the WT corporation in to abject servitude. Say a person warns his friends and relatives about the fraud and he is DF'd for doing so? I think if in that order they might has a 1st amendment violation.
Intentional infliction of emotional distress is such a high bar that few people can ever reach it in the huge number of legal proceedings a year. There is no assault or other criminal act either.
That why a good expert witness could really help the case.