That came to mind, but that also opens a whole new can of worms as you haven't been employed by one individual to investigate one person EG: divorce situations, wife hires P.I to investigate Husband ect.. Your pretty much just filming random people.
Just look at the controversy with people using camera's at beach's, school events ect.. It's clear they are after someone to target the younger driver's... It will take one kids father/mother who is a barrister to sue the ass out of them