Then i would wager time has softened your memory of being in the thick of things and/or you were fortunate in the children you were gifted with. If you cannot understand that maybe this is a father thats loves his daughter, but that the effects of adolescence in his daughter has them at odds, maybe has her doing other rebellious acts that has worn his patience out. You should be able to relate to that right? You raised 4, you should be well aware.
Do you seriously think he went to that much trouble, threw his own money away, over one post on facebook? No, much more likely that was just the proverbial straw and he has reached a point of hes not putting up with one more iota of her bad behavior.
Ill tell you the effect this will have on his daughter, i bet she wont publically insult her parents again. Parents who work to feed her and clothe her, who protect her from the big bad world, who make sure shes getting a good education, who provide to her the things she wants and needs.
Sure as parents they have a responsibility to provide these things, but that does not give her an open license to spit in their faces, privately and sure as hell not in a public place.
She most likely got exactly what she deserved, maybe the whole debacle will jerk a knot in her ass and make her fly straight.
Tough love has its place.