If they're sitting on a bench and have the phone held up in front of them presumably there's not much visible besides a bit of wall just behind the person. But YEESH, what if you fat-finger and accidentally change to the rear camera? What if you drop the phone? What if you stand up without thinking? What if you're actually a creep and using this as a ruse to hide that you're filming people?? There's just SO many ways this could go wrong! Maybe just DON'T!