No Hats
Seen on a recent trip to San Antonio, Texas, which is probably the last place you’d expect to see any attempt to constrain the use of any kind of headwear.
Obviously they don’t mean you can’t wear your own hat while taking photos; what they want to prevent is people wearing the display hats for the purposes of having their photographs taken. Or at least I think so; there were no hats in the vicinity of this particular notice.