NBC Sports did a quick write-up about this. They quoted an interview they say Thornton gave "recently". Here's a quote:
He recently spoke out in favor of fighting, while a debate about whether that element should be taken out of the game rages on.
“I don’t know the numbers so I probably shouldn’t [say] but I think a lot more concussions are happening from head hits than fighting, but any time anyone gets punched in the face and gets hurt, people jump all over it,”he recently told Katie Strang of ESPN.
“I think there’s an agenda. I’m not sure where it’s coming from. I won’t say it’s changing the tide, but I think there’s definitely more of an agenda nowadays.
“People could probably criticize that I’m a little too honorable, I suppose, in some instances. I’ve been a firm believer my whole life that what goes around comes around.
“If you’re one of those guys that suckers someone when they’re down or you go after somebody that doesn’t deserve it or isn’t the same category as you, that will come back and bite you at some point, too.”