I agree with what she was doing when she was killed, and if she felt strongly enough about the US that she wanted to burn its flag, more power to her. Its called freedom of speech. Worshipping a flag makes no more sense than worshipping a god. I'm surprised some entrepreneur hasn't come out with a line of toilet paper embossed with the flags of various nations, so you can REALLY show your displeasure with a nation of your choice.
I know someone who once pissed in the "peace flame" at the N end of the Burrard Bridge, putting it temporarily out... he later went on to be an upstanding citizen. I myself have smoked some BC 420 lit up in that very flame, "peace man". I've never yet lit a joint from a burning flag, though.