As someone who frequently has to dart myself and my puppy out of the way of these jerks—almost always on a narrow sidewalk beside a busy arterial—this kind of sounds nice. But I can’t imagine how it would work. Even if I could scramble fast enough to snap a picture while keeping pup safe, would it be actionable?
As it is, on the rare occasion it’s just me out walking I’m content to play chicken with them and try to hold my ground. But I don’t take those chances with pup, and trying to get evidence (however useful) would involve the same risk.