The problem is too many people excercising their "rights" without takling a moment to think about their responsibilities. You can't have one without the other.
People must have the freedom to protest about whatever they want, whether its pro gay marriage, anti abortion or wanting the UK out of Afghanistan, but they have to be made aware that with that right comes responsibility and consequence.
Inciting someone to break the law must incur a penalty, whether it is a fanatic pretending to be a muslim (because lets face it - these people are not really religious) or the EDL encouraging people to burn mosques or even the guy shouting racial abuse at the football match.
Whether that consequence is deportation or prison will depend on the individual circumstances, but we must be able to punish those who preach hate and violence regardless of race, religion, gender or whatever motive they have.