All this, plus the well-established legal notion of “informed consent”. If I rent a megaphone from a shop it would be utterly unreasonable for that shop to tell everyone I’d bought a megaphone - I wasn’t informed and wouldn’t reasonably assume that’s what they would do, so I couldn’t consent - but if I walk around using that megaphone to shout at people it would similarly be utterly unreasonable to argue that the shop is responsible for keeping my bellowings private.