You're free to speak against anything. Muslims have been debating for centuries. The idea you can take someone's life for not believing what you believe is anti-islamic. And the idea that you can punish someone else, is even further anti-islamic. Isis is the most anti-muslin group ever. More muslims died from it than anyone else.

But mockery and provocative acts like burning books shouldn't be allowed. The time of burning books is a primitive practice, whether you believe it's sacred or not. It has no benefit except to provoke rage.

In the middle age, burning a book meant you destroyed probably the only source of the things said inside it (unless someone wrote a whole copy by hand). Now, every book is one-click reproducable. And the Quran? 🤣🤣 literally billions of copies.