I do not. While we have the right to freedom of expression under our Constitution, I believe that there are better ways of expressing our dissatisfaction with certain aspects of our customs or laws. To disrespect our national anthem or our flag, or both, is disrespecting our country as a whole. If a person has so little respect for the mother country who nurtured him or her and gave them the privileges, and the freedom to express his or her opinions, that person should respect the country as a whole, then go find some other way to remedy the situation he or she does not like.
Martin Luther King Jr. is a great example of this. I don't recall, historically speaking, a situation in which Rev. King disrespected our flag or our national anthem. He knew that in a country that did not have our constitutional rights, he would be arrested immediately and sent to a gulag. Unfortunately, he was eventually assassinated for what he believed in, but it was murder by crackpots and had nothing to do with the government.
These people who are using our national anthem or our flag for their personal vendettas should go spend some time in Russia or Communist China. Having to constantly watch one's backside and one's mouth is a great attitude adjuster and might just scare some sense into them. While I was not previously a protester, I found it comforting to get back onto U.S. soil after a student trip to the Soviet Union, and I would have felt the same way if I had been African-American. Our group had some scary close calls.