Many a family has seen their name dragged through the mud over the horrible deeds of one.
It helps to show that just because two people are related does not mean that they share the same views.
This was lost on the left when discussing Osama bin Laden's 20+ siblings and countless cousins etc.
In reference to having shame in a family for what a brother has done I think back to the Doctor who treated and helped John Wilkes Booth escape after assasinating Abraham Lincoln. The Doctors last name was Mudd.
Because he was branded a traitor for participating in the conspiracy, the term "Your Name Is Mudd" was coined as being derogatory. His own family members were shamed by Dr. Mudds' actions and literally had to hide from persecution. All just because they were related to a man who helped the murderer of President Lincoln.
Perhaps our Arab American friends should take some American history lessons? They might better understand the shame and other consequences of keeping silent when their brethern are plotting murder and destruction against Americans. Our history of retaliation against conspirators who harm our own is well documented.