I am scared.. for this world

I condemn the tasteless and dis-respectful cartoons published by Europian news papers. However the way global protests are being carried out to these cartoons terrifies me.

Shocking thing is, most of these images are from Europe itself. I can not imagine about the protests in muslim countries.
http://varifrank.com/archives/2006/02/the_messenger_1.php

Somebody who has tarnished the prophet has to be killed, slayed, beheaded, extreminated, masaccared. Europe has to pay with their 9/11. Europe has to pay with another 7/7.

I wonder where werre these millions of protestors when -

1. Terrorists killed thousands of people on 9/11.
2. US bombed a marriage hall in afganisthan and killed many civilians.
3. Terrorists killed hundreds on 7/7.
(Other such events).
4. When (supposedly) a state government was involved in mass riots.

Does killing of innocents is a lesser crime than tarinishing a prophet ?

Do they really mean what is written on those placards ?

Should tarnishing the prophet be paid back with violence all over ?

If such things can arise out of a cartoon, what would be the situation if say more serious things happen against the faith of Muslim people ?

Would that start world war 3 ?