I've never heard of that. It's definitely not legal. If I had paid to go see a play that I knew and liked and this happened I would be extremely angry. I would never go see another play from that group again. If I was an actor and this was going on and allowed to go on I would seriously consider walking off (well, I guess not but I would be VERY upset.) If I was a director and that happened, I would be backstage ASAP and put a stop to it with the clear admonition that anyone who didn't stop would be not be cast by us again. Maybe after a long, LONG run on the professional stage but for us we're putting on shows for 5-10 performances max, and a lot of people in the community including relatives and friends don't get there until the last night. That just seems completely self indulgent and bush league. You put in too much work to just blow off one of the few performances you have.

Just my opinion.