To slander someone is an offence that can be taken to court.
The reason they don't understand is because the Prophet Muhammad (peace and blessings be upon him) means nothing to them. Jesus (upon him peace) is slandered with an array of different insults which I equally disagree with.
You see for a people without faith this is difficult to understand.
Freedom of press is intrusive to most stars, they don't like being photographed on holiday or whatever.
People can express opinions nobody has a problem with that but as soon as you begin to offend or insult then you have crossed the line. Its as simple as that.
Many people in the west don't realise that they are controlled by the press and media. Then how can a system be just if its insulting and slandering people never mind Prophets and say well its okay, freedom of the press.
Freedom of the press was one of the worst tribulations of Princess Diana's life.
So if a person commits a crime they have to pay the price, its a simple as that. If only they knew who Muhammad (peace and blessings be upon him) they would understand.
On a different note many scholars have said this the people who drew the cartoons, did not draw him, they drew us.
They don't know him but they know us, Muslims really need to think about this.