IOT is an acronym for the Internet of Things. As more and more devices are given internet access, the possibilities of abuse and security breaches increases dramatically. For example, your television could provide a hook into your home security that allowed your web cams to be monitored by an outside source. Or, your “smart home” could be hacked to broadcast when you leave the house so thieves would know when the best time would be to break in.
These articles cover some of the security issues, and how to work around them. The first and foremost thing you should do, however, is change the password on your router.