John Locke (and many other political philosophers) drew a line between liberty and license, liberty being those rights which people ought to have and license being those freedoms people ought not to have. For example, you do not have the freedom to punch somebody in the face if you don't agree with them. The Bill of Rights is meant to be a structure that supports the freedom of the people to accomplish their own ends as they see fit, not to be some kind of free zone, licensing every act imaginable. As Justice Oliver Wendell Holmes Jr. stated, "The most stringent protection of free speech would not protect a man in falsely shouting fire in a theatre and causing a panic."
There's another component to this, responsibility and liberty. Basically it means that if you demand liberty, then you also agree to act like a responsible person. It's bizarre that we have to actually spell this out in the modern era, but it simply means you can't run around acting like a two year old and expect society to not treat you like a two year old.
For a long time, this sect has violated societal norms, violated the spirit of our freedom of speech responsibilities, and really, in effect, screamed "fire" in a crowded theater over and over again. Their speech has no other purpose than to incite. They should be forcibly removed, arrested, cited for disturbance and have their assets confiscated.