I used "trespass" as a transitive verb. It's a remedy, not something the hypothetical photographer is doing. It's when a person who controls a property can dema

I used "trespass" as a transitive verb. It's a remedy, not something the hypothetical photographer is doing. It's when a person who controls a property can demand you leave and not return under penalty of arrest. It's not linked to photography specifically—a person who controls a property can trespass you for virtually any reason or no reason at all. They can't make you delete your photos or anything else. The hypothetical photographer is only trespassing when they've been given notice that they need to leave (i.e. the person who controls the property has trespassed them) and they refuse to do so. Again, this is not a grey area at all.