Not all Muslims become involved in acts of violence.....

“ Not all Muslims become involved in acts of violence. Yet all might be held culpable. THis is because that section of Muslim--in fact, the majority--who are not personally involved, neither disown those members of their community who are engaged in violence, nor even condemn them. In such a case, according to the Islamic Shariah itself, if the involved Muslims are directly responsible, the uninvolved Muslims are also indirectly responsible. (p. 91) ”

Maulana Wahiduddin Khan

From : The True Jihad: The Concept of Peace