But they can't just demand that you identify yourself because they want to know who you are, and then arrest you if you refuse. Or at least..they aren't supposed to.
BUT the whole basis of why the cop pulled him over to begin with was because of a complaint by the Farm and the Farm security had followed the guy until the cop showed up.
A complaint about someone doing something that isn't illegal isn't sufficient.
I'm telling you. Cops don't have the authority to demand identification from people based on the fact that they just don't like them being where they are, doing what they're doing, if where they are and what they're doing is LEGAL. They have to first have a reasonable suspicion of some sort of wrongdoing, and they have to be able to give voice to that BEFORE they demand identification. You can't just walk up to someone and say "hey you, I don't like you standing there so you have to give me your name so I can look to see if I can arrest you for something else".