Yes. So do I. But I am not going to deny their First Amendment right to do so.
The 1st amendment does not specify freedom of action or the freedom of arson. The Constitution does not give rights. See the 1st amendment:
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
Burning a flag is not speech. Burning a flag is not a peaceful assembly. It is not a petition. It is not any form of religion. This amendment applies only to Congress, in that they can pass no law concerning what one can say, what one can petition for, preventing the peaceful assembly of people, limit what people can print, post, produce a video, or cover in any newspaper. They can pass no law establishing a Federal religion, nor can they pass any law that outlaws any religion.
These restrictions apply only to Congress (the federal government). They do not apply to the States. They can pass any of these things legally (and have done so), according to their own State constitutions.
No document gives any right. The Constitution specifies limits to the government to keep their hands off rights you already have.
Burning a flag you don't own is arson and destruction of private property. That's a crime.
Commandeering city streets is theft, intimidation, and kidnapping. Those are crimes. There are residents on those streets that are trapped in there. There is no road anymore.
Defacing buildings you don't own is a crime. It is vandalism.
Nothing in the 1st amendment prevents any government from passing laws against these activities. See the Constitution of the United States and your own State constitution (unless you live in the SOTC, which currently has no functioning constitution).
There is nothing in the 1st amendment that prevents any government from passing any law about burning a flag. It is neither speech nor a religion nor a petition nor an assembly of people. The 1st amendment is not binding upon the States. It applies ONLY to the federal government (Congress). However, State constitutions typically contain similar wording that DOES apply to State and local governments in your State (if you are living in a State of the Union).