Electricity company controls customers' thermostat settings during a warm day in Denver.

According to KGMH-TV, some 22,000 customers (who voluntarily enrolled in
the AC Rewards program offered by their electricity company) had their
enrolled "Smart" (IOT enabled) AC thermostats locked at 79 F (~26C) due to
an "energy emergency" when the temperature in Denver approached 90F (32C).

This program is voluntary (for now).

KGMH-TV report:
https://www.thedenverchannel.com/news/contact-denver7/thousands-of-xcel-customers-locked-out-of-thermostats-during-energy-emergency

Details of Xcel Energy's AC Reward program:
https://co.my.xcelenergy.com/s/residential/heating-cooling/ac-rewards

controls customers electricity settings