Iain, "shooting the bird" as crime is a function of court decisions. No consistency, either.
Some courts have held that it's an expression of free speech under our First Amendment.
Other courts have held that it's a provocative gesture, and have thrown out assault charges against somebody who struck the person making the gesture*.
Whether or not somebody is monitoring what a camera sees, however, I have a certain amount of difficulty in making the charge as was done in England. After all, shooting the bird at an inanimate object at most would merely be "crime agains camera", and would harm nobody.
It's not like the guy painted the lens or bashed it with a cricket bat!
Art
* Years back, my buddy Big Luke was a wrecker driver. He got hooked on to a car for repossession, and was in a hurry to leave before any public confrontation occurred. A city bus pulled up and stopped, blocking him from leaving. Luke yelled at the driver. The driver ignored him and continued to write in his log book. Luke yelled again, and the driver shot him the bird.
Luke leaped out of his truck and charged into the bus and pounded on the driver. Luke climbed out and the bus went away. However, the driver filed charges.
In County Court, the judge listened to the complaint, and then turned to Luke for his version of the story. "Well, yes, Your Honor, I did hit him, but not until after he shot me the finger."
The judge looked at the complainant, who admitted that, yes, he had indeed done that.
The judge held that if Luke had only thrown one punch, she'd have let him off. However, he'd gone too far for the particular provocation.
"That will be $47.50, fine and costs."
Luke responded with a classic: "Your Honor, can I give you $95 now, and wait for him outside?"