This is exactly what just happened to me in my sold out theater.
I'll post my review again, since it wasn't seen before:
The critics are so, so, sooo wrong. This movie was absolutely phenomenal, and the sold out crowd in my theater was consistently engaged, responsive, and they applauded loudly at the end. They ate up every second of this. It was probably the most engaged crowd I've been a part of since TDK in 2008. And to those hating on Leto's Joker, the crowd (and I) seemed to absolutely love him too. Everything about this movie was likable and satisfying from beginning to end. I have no idea what the world is smoking, but they're entitled to their opinion... but damn, I have no clue how anyone could dislike this film. A high 9/10 for me, without question.