With all due respect, I think it makes perfect sense. Sure, it's not their house, just like it ain't anyone else's flag but her own. She bought it I assume, but still..
It's not a matter of who's house, or who's flag, freedom of speech / expression, etc. it's a matter of having respect and common sense.
Just because something isn't illegal, doesn't make it right. Just saying...
Her taking a "piss" on the flag just shows what kind of person she is. Although like I said before, and I still stand by it, (even though she did something very stupid imo) people threatening to murder her and harm her family because of that "stupid" choice is a little much for what she did.
I mean, I see why some may be angry with what she did, but making murder threats is going too far.