The smarter your stuff, the less you legally own it. And it won't be long before, besides resisting you, things begin to quietly resist each other.
Objects with computers in them (like phones, cars, TVs, thermostats, scales, ovens, etc) are mainly software programs with some sensors, lights, and engines attached to them. The hardware limits what they can possibly do — you can't go against physics — but the software defines what they will do: they won't go against their business model.
In practice this means that you can't (legally) install a new operating system in your phone, upgrade your TV with, say, a better interface, or replace the notoriously dangerous and very buggy embedded control software in your Toyota. You can use them in ways that align with their business models, but you have to literally become a criminal to use them otherwise, even if what you want to do with them is otherwise legal.
Bear with me for a quick historical digression: the way the web was designed to work (back in the prehistoric days before everything was worth billions of dollars) you would be able to build a page using individual resources from all over the world, and offer the person reading it ways to access other resources in the form of a dynamic, user-configurable, infinite book, an hypertext that mostly remains only as the ht on http://.
What we ended having was, of course, a forest of isolated "sites" that guard jealously their "intellectual property" from each other, using the brilliant set of protocols that was meant to give us an infinite book just as a way for their own pages to talk with their servers and their user trackers, and so on, and woe to anybody that tries to "hack" a site to use it in some other way (at least not without a license fee and severe restrictions on what they can do). What we have is still much, much better than what we had, and if Facebook has its way and everything becomes a Facebook post or a Facebook app we'll miss the glorious creativity of 2015, but what we could have had still haunts technology so deeply that it's constantly trying to resurface on top of the semi-broken Internet we did build.
Or maybe there was never a chance once people realized there were lots of money to be made with these homogeneous, branded, restricted "websites." Now processors with full network stacks are cheap enough to be put in pretty much everything (including other computers — computers have inside them, funnily enough, entirely different smaller computers that monitor and report on them). So everybody in the technology business is imagining a replay of the internet's story, only at a much larger scale. Sure, we could put together a set of protocols so that every object in a city can, with proper authorizations, talk with each other regardless of who made it. And, sure, we could make possible for people to modify their software to figure out better ways of doing things with the things they bought, things that make sense to them without attaching license fees or advertisements. We would make money out of it, and people would have a chance to customize, explore, and fix design errors.
But you know how the industry could make more money, and have people pay for any new feature they want, and keep design errors as deniable and liability-free as possible? Why, it's simple: these cars talk with these health sensors only, and these fridges only with these e-commerce sites, and you can't prevent your shoes from selling your activity habits to insurers and advertisers because that'd be illegal hacking. (That the NSA and the Chinese gets to talk with everything is a given.)
The possibilities for "synergy" are huge, and, because we are building legal systems that make reprogramming your own computers a crime, very monetizable. Logically, then, they will be monetized.
It (probably) won't be any sort of resistentialist apocalypse. Things will mostly be better than before the Internet of Things, although you'll have to check that your shoes are compatible with your watch, remember to move everything with a microphone or a camera out of the bedroom whenever you have sex even if they seem turned off (probably something you should already be doing), and there will be some fun headlines when a hacker from insert here your favorite rogue country, illegal group, or technologically-oriented college decides technology has finally caught up with Ghost in the Shell in terms of security boondoggles, breaks into Toyota's network, and stalls a hundred thousand cars in Manhattan during rush hour.
It'll be (mostly) very convenient, increasingly integrated into a few competing company-owned "ecosystems" (do you want to have a password for each appliance in your kitchen?), indubitably profitable (not just the advertising possibilities of knowing when and how you woke up; logistics and product design companies alone will pay through the nose for the information), and yet another huge lost opportunity.
In any case, I'm completely sure we'll do better when we develop general purpose commercial brain-computer interfaces.