The correct answer to this open question is the following.
Non-violent resistance can be successful to organize protests and demonstrations like the ones organized by civil rights groups in the southern states during the 1950s and 1960s.
Indeed, that is my example. Well, I have two. The first one is the non-violent resistance and marches led by Hindu Mahatma Gandhi when he was the leader of the independence movement in India.
The other example is Dr. Martin Luther King Jr. Dr. King always defended his non-violent approach to protest, although many people criticized him, including other African American leaders.
Regarding the issues that I feel non-violent resistance could encounter are precisely the violent reaction of police or opposite groups that use violence and fear to intimidate.