Gavin DeGraw thinks everyone -- including Sinead O'Connor -- has a right to tell anyone to go f**k themselves ... because this is America dammit!
We ask Gavin about the crap Sinead is both taking and dishing out after she cancelled a few concerts and fans went on an Internet tirade against her. She blasted back in kind.
We got Gavin after he landed at LAX ... we're guessing he flew American.
Waiting for your permission to load the comments.