I'm old enough to remember when patrons would be hassled if they tried taking pictures at any kind of theatrical or musical performance- it was just universal.
Things have changed. There will still be shows that ban it- but today there is a much more enlightened thought process around recording of performances. A friend tweeted last night about taking a gazillioin pictures of a show at Disney with his new professional grade rig. Its the kind of camera that would have been confiscated ten years ago, but is now encouraged. Disney realizes that my friend is going to show his cool photos to all of his friends, and will be some of the best marketing they could buy. Their only "cost" is letting my friend's stills out into the world.
Granted, if my friend tries to make a buck of those stills the Disney lawyers will be all over them, as they should be. But both sides understand the value of letting users create and share content derived from your original performance, as it becomes win-win.
Let your users play and share.