I totally agree too if there is a history of boundaries crossed, critisizm and such, any even unintentional behavior would set off bells and whistles.
I guess what I am saying is this (trying again because I'm just really struggling trying to figure out what I mean. It sounds right in my head!)
My DIL has a history of being a pain. She has a history with me or eye-rolling, foot-stomping, aloofness, coldness, etc. I had situation after situation with her that no matter what I did, it wasn't working and neither could anyone else get along with her. So when the final straw came of her booting myself and my family off her FB, after nothing happened, at that point I had enough, I didn't send her a venom filled email full of contempt and hate. I didn't send something raking her over the coals. I simply sent a text to my OS saying that I didn't appreciate being lied to by him and it was obvious at this point that they didn't want anything to do with our side of the family, so I was honoring their wishes and would no longer contact them. Told him I loved him and he knew where to find me if he needed us. That was all. I could have sent an enraged email but I didn't. What good would it have done? All it would have done was make it worse and harder to maybe have a relationship in the future if things changed. I would have been wrong to do it and would have owed an apology for it.