I believe any and all forms of propaganda are dangerous, propaganda is designed to trick and lure people into thinking a certain way and it always ends up badly, I think propaganda should be strictly limited or outright outlawed in modern society we have all seen the results of what happens when it gets out of hand.
There should not be any limits on any form of free speech in this country. This country was founded on the principal that everyone would have a voice and be able to be heard. If they are speaking about hate and a message that could cause someone harm then I believe that they should be limited but if the message is just radical and a person is trying to express themselves then it is not a problem.
In the United States there is freedom of speech, this is an important tenant of the whole structure of society. Any limit on that is dangerous. Who is to decide what is extreme and what isn't? Not allowing people to express extreme views does not stop them thinking it, and sometimes hearing extreme views help people oppose their positions.
I do not think that there should be a strict limit to extremist propaganda in the United States of America. Just because I do not believe in them does not mean I want to limit the free speech of other individuals. Of course, if anything is against the law, then the law should step in.
Even though it is bad, extremist propaganda is part of free speech and it is important that all free speech is protected - not just the parts that we like. However, people should speak back against it just as loud and make sure that people know what it is about and that it's propaganda.