Someday in the far future, when creatures are born from sentience modules that can be easily embedded into other living, non-sentient, or even non-living objects, humans became capable of communicating with pretty much anything, creating a truly intelligent internet of things and not a single entity is controlling it - not even us.
We've figured out how the soul works, hardcoded it into the smallest computer we know, wrapped it up with a nice little object-specific shell interface, provided it with whatever renewable power works well with the interface, and just handed it to anything, anywhere, anytime, anyone we want.
You want a pet rock? Here you go. You want to marry it/him/her? Sure, why not. You wanna have kids with it/him/her? Uh. that's a bit problematic but, sure. Why the hell not? Wait. Are you a Vacuum Cleaner 3000 or a Vacuum Cleaner X-series? Because of you're one or the other, we might have to ask you to talk to different papers first.
Giving away souls like its Halloween and everything your eyes can see are trick-or-treating sounds like a lot of fun, until you realize your toilet bowl can have the same rights as you have.
And the fun goes out the window when the whole planet just earned its own human-derived consciousness. Now, we might have known it before and didn't really thought about it that much, but now that our planet, volcanic zits and underwater ridges and all, has the same rights as we are, speaking the same language we do and maybe more, how are we going to respect each other?