Deviance can be a powerful tool to encourage social change. Why does deviance encourage this change? I believe the answer is simple. Deviance sets in motion inside of everyone's head a thought process. People begin to think positively and negatively about what happened, especially when it is highly publicized deviance. Opinions are formed and about what has happened. People begin to debate with each other about who is MORE wrong.
For instance, its 7:50am and Bob an average working citizen is driving to work. Bob sees motorist after motorist get pulled over and issued a speeding ticket on a daily basis. Bob's thinks about this everyday when he sees someone getting another ticket. Bob's opinion changes because many people are getting speeding tickets. Bob no longer thinks those people shouldn't be speeding. Bob thinks it is unfair to pick on common working citizens for going to work. One day at work Bob receives a memo from a fellow employee to protest the high volumes of speeding tickets at a public place.
The protest gets out of hand and there is a huge riot. The Business institution where Bob works is vandalized. The Military is called in because the police who were issuing the tickets couldn't handle the protestors turned rioters. This riot becomes publicized through the media. Protests and riots take place countrywide. It's a huge mess. Many social institutions are affected by what is taking place.
Why would this cause social change? Social institutions rely on each other to operate. Businesses can't run because of the riots. Schools are closed for fear of possible rioting. The economy suffers because no one is working. People can't go to church because of rioting. Hospitals are filled with people injured in the riots. Bob's family doesn't have the money to pay bills...