https://www.vice.com/en_us/article/88n5b3/smart-thermostats-are-turning-down-air-conditioners-during-heatwave

As the Electric Reliability Council of Texas (ERCOT) urged residents last week to limit their energy use and avoid shorting the grid amid high temperatures and demand spikes, a number of Texans with smart thermostats were dismayed to find that this was being taken care of for them. 

Brandon English, of Deer Park, Texas, for example, returned home from work last week to find his house right at 78 degrees fahrenheit, the temperature ERCOT recommended to reduce grid strain. But English wasn’t the one to set it there: It had been changed by a third party while his wife and child were napping.