Sheikh Nimr al-Nimr: Who is Saudi Arabia's most vocal Shia critic sentenced to death and crucifixion for dissent?

Sheikh Nimr al-Nimr: Who is Saudi Arabia's most vocal Shia critic sentenced to death and crucifixion for dissent? 
© AhlulBayt News Agency - ABNA - Shia News 

Sheikh Nimr al-Nimr is also Ali al-Nimr's uncle, 
the juvenile protester sentenced to die the same way. 
there is an Action for him in my sidebar.