In other words, TV viewing patterns will be used to serve ads to any device user who happens to be connected to the same network as the Vizio Smart TV — an obvious problem for households with a mix of say... adults and children?!
Vizio does provide instructions for disabling the Smart Interactivity features and says that “connected” features of the device aren’t contingent on monitoring. That's better than some other vendors. In 2014, for example, LG used a firmware update for its smart televisions to link the "smart" features of the device to viewer tracking and monitoring. Viewers who applied the update, but refused to consent to monitoring were not able to use services like Netflix and YouTube. (https://securityledger.com/2014/05/bad-actor-with-update-lg-says-no-monitoring-no-smart-tv/)