The Google patented product Nest contained a vulnerability which would allow hackers to pinpoint houses via the internet which used the Nest product. The product would send zip codes over the internet in plain-text and this is a big no no.
Researchers at Princeton University performed the research on the Nest product and they stated that:
Until recently, Alphabet’s popular Nest thermostat was leaking the zip codes of its users over the internet. This data was transmitted unencrypted, or in the clear, meaning that anyone sniffing traffic could have intercepted it
The research mainly focused on discovering what kind of information was being leaked by smart devices and “IOT” devices.