The crucial difference here is that they're burning their own books, not confiscating anyone else's. To that end, I don't see this as any limitation of Rowling'

The crucial difference here is that they're burning their own books, not confiscating anyone else's. To that end, I don't see this as any limitation of Rowling's right to express herself (although the general level of outrage at her right now might cause publishers to think twice before signing a contract with her). And liberals symbolically destroy stuff they don't like all the time. It isn't conservatives who are burning American flags at anti-war/cop protests. I'm generally of the mind that as long as it's your property, you should be able to do what you want with it, but I've never seen the point to this kind of radical symbolism. A movement for social justice might start with a radical fringe, but its overall sustainability and success rely on convincing people who don't already agree with the cause. And most attempts at social change, especially those regarding civil rights, already have to fight an uphill battle against accusations of dangerous radicality. Going Fahrenheit 451 on books you don't like is not going to help with that perception.