Trying to stop this behaviour is applying the selection pressure that will make them better at it.
The comments range from anodyne to sometimes actually quite useful.
Of course it's often going to be a regular human pasting from chat, or maybe it might be an agent using openclaw or other agent framework that someone installed voluntarily. But maybe, just maybe, one day you'd find one or two feral escaped agents, sneakily passing messages where no one pays attention. O:-)