That is not actually an American Flag, it only has 10 stripes. The real one has 13. I find it amusing that he was dumb enough to light the flag with gasoline on his arm like that. Stupidity bought him the 3rd degree burns, not burning an American flag. He has the right to burn one just like you or I should have the right to burn one. What is a flag? It is a stupid peice of fabric with designs, it is an icon. Icons should not be worshiped, it is the idea that icon stands for that is important. They can burn the flag all they want, but they will never destory the ideals of freedom and equaility it stands for.
On a slightly different tangent, just because he burns a flag does not make him a terrorist. A little logic here, we know that he is burning a flag (p), but we do not know if he promotes the use of violence to achieve his political agenda (q). In this case p !=> q.