My city sells dated and timed permits for "professional" (sic) photographers to shoot at city-owned parks and properties. The permits are also specific about location within public spaces, which limits the likelihood of this sort of scene. I've had hacks try to push me, friends and family out of spots that are not designated; few when asked have permits and out themselves usually with the old "it's a public park, dude." Very few pros in my area bother with this sort of lowball engagement, wedding, portrait work which is now the realm of self-important poseurs. They're making it rough for everyone, so I'm often guilty of telling them to f-off till I'm done. As for their clients' innocence, it's often a look-in on what sort of schlock they'll be asked to pay for. Not my worry.