If you do something ugly or inconsiderate expect to be called on it.
Being called on being ugly or inconsiderate is different than being threatened with violent death. I hope you can see the difference. If Revolution Muslim wanted to boycott Comedy Central or its advertisers, if they wanted to picket or march in opposition to the South Park episode I would support 110% of their right to do so, even if I do not agree with them.
Re: I never know what is meant by free speech in this context?
Being called on being ugly or inconsiderate is different than being threatened with violent death. I hope you can see the difference. If Revolution Muslim wanted to boycott Comedy Central or its advertisers, if they wanted to picket or march in opposition to the South Park episode I would support 110% of their right to do so, even if I do not agree with them.