Someone emailed me a video the other day. There is a rock musician who is extremely popular in the non-Jewish world. He is also a Jew. His family is frum, and his grandfather was a Rav. He once said he had to choose between being a rock star and his religion, and he chose to be a star. Obviously, he is no longer observant at all.
Anyway, in this video, he is giving a concert, and it is between songs. Apparently there were some chassidim sitting in the front row. He called them out on it. He told them he's Jewish, and knows all about frum Judaism and chassidus. He told them they have no place at his concert. He also said that while he doesn't believe in hell anymore, he knows they do, and that they will probably end up there for attending his concert.
The Gemara brings down the story of the man who did teshuva because of something a zonah said to him (I'm blanking on the name right now... Yehudah ben something, isn't it?) Here we again have an immoral person giving mussar to some people who obviously need some. Hopefully they'll learn something from him!