Is there ever a time to take the law into your own hands?

Is there ever a time to take the law into your own hands?
Recently my cousins wife bumped into a man that had sexually abused her as a child. The abuser had moved back to the area where she lived.
The abuser was well known to my cousin (although he didn't know what he had done). When she confessed what he had done to her, my cousin paid him a visit and exacted punishment. He was the judge and the jury that day.
After the punishment, he gave the man 24 hours to leave their city, never to return again.
The abuser duly obliged, and my cousin and his wife moved on with their lives as best they could.
My cousin had initially told his wife to go to the Police and report the abuser, but she refused; and so he elected to take the law into his own hands. He was ready to do the jail time required if necessary.
Personally I would have done the same, had I been in the same situation. Sometimes the law just can't deliver justice; and a man has to exact his own.