You need to slightly modify your post. There are different types of terrorism, such as religious terrorism, drug-related terrorism, communist terror.etc. There are non-Muslims involved in some types of terror, such as the NDFP / NPA of the Philippines. But 99% of the terrorism motivated by religion are committed by Muslims.
yup please be specific mate of what terrorism you are really refering to. anyway, it is not all muslims are the only responsible in any terrorist attacked. they were also diffrent religions who are involved too. but i also agree with sithara007, that most of these terror attacks were headed by muslims and we cannot blame if some will stereotype the muslims that they are terrorist because mostly they were responsible of such acts. most terrorist came from such religion.