This I can relate to. I often attend concerts at a casino. Noticably posted in numerous places, outside and inside the concerthall, including on large signs on both sides of the stage, is a statement explicitly prohibiting the use of any and all photography or video equipment. I knew of this sort of rule at concert venues, so I didn't even consider taking my gear. But as you say, there were people everywhere taking pix and video with smart phones, and lots of them were even using flash (which works REALLY well when you're sitting in the thirtyth row, you know....). I had to ask a girl directly in front of me to please stop blocking my view by holding up her smart phone and capturing videos. The third time, I thratened to get the attention of a security guard if she didn't stop. She gave me the single finger salute. Next time she did this, I waved and got the attention of the guard. He walked over and took the smart phone out of her hands and told her she could pick it up at the ticket desk after the casino IT guys had erased all the concert video from it.