The internet as we know it is nearly 25 years old (that's the world wide web: the pre-web internet is a lot older, and not far off its 50th birthday, but would be unrecognizable to most people today). We're using it for purposes the designers never anticipated, and a myriad of hopeful experiments flourish on the web ... and sooner or later die, or crumble into gentle decline and benign neglect.
And sometimes the neglect is not so benign.
Recently the news broke that internet-connected toys were being hacked. CloudPet stuffed animals have a web connection that allows kids and their parents to send and receive voice messages; they're sold as "a message you can hug". But it turns out that their login database was unsecured and discoverable via Shodan, "the search engine for the internet of things", and huge numbers of logins have allegedly leaked (they didn't password protect the password database—or encrypt/hash/salt the passwords in it). Voice messages for CloudPet users were stored on Amazon's AWS cloud service without authentication, so I leave the mis-applications of this service to your imagination.
The worrying part is that the toy manufacturer was extremely difficult to contact and doesn't seem to have any timely process for monitoring or fixing defects in the service (not to mention probably being in violation of the Data Protection Act if the toys are sold in the UK). And of course the toys will probably out-live the company; the half-life of a corporation is 15 years (for a start-up it's about 18 months) but the half-life of a beloved toy may well be considerably longer.
Note that Shodan isn't to blame for the sloppy security practices of a novelty toy manufacturer, any more than Google is to blame for the existence of child pornography on the internet. But there are a lot of novelty toy manufacturers out there, and more and more of them are going to go bust every year, leaving broken toys behind them with no internet connection ... or worse: be taken over by larger corporations who will simply fold the developers into their own teams, continuing to pay the rental on unattended and unpatched servers for the obsolescent product lines until nobody screams when they turn them off. (Google, Nest, Jawbone, I'm looking at you.) Then there are the unattended child monitoring cameras with microcontrollers running unpatched ancient linux distributions with default passwords. And the home security systems/burglar alarms. Internet-controlled smart front door locks (there'll be an app to break that). Network-controlled drones probably aren't a thing yet (unless you're the USAF), but they're doubtless on their way. Internet-connected vibrators have already triggered lawsuits; if you put the data from a We-Vibe together with the owner's NetFlix or smart TV watching habits, or PornTube click-trail, you can probably build up an interesting picture of their predilections. And so on.
What are the unanticipated downsides of the decay of the internet of things, combined with poor security practices and developers going bust and leaving infrastructure in place as abandonware? You probably know I've got a vivid imagination by now—what haven't I anticipated?