"We're looking forward to continuing our great partnership and remain devoted to you above all else," wrote Nest founder Matt Rogers in a blog post to consumers Monday. "We know you entrust your homes and information to us and are committed to protecting that the same way we've always done."
Last year, Google Ventures, the search giant's investment arm, plowed $80 million into the start-up. Two weeks ago, Nest raised another $150 million in funding, indicating the company may be valued as high as $2 billion.
That was before Google finally snapped up the company for a price that was 60 percent higher than even that.
"Google wasn't kidding when it was saying it wanted to organize all the world's information, I guess," joked Jay Stanley, a senior policy analyst at the American Civil Liberties Union.
While Nest insists its customer data will be used only for improving its services, it didn't rule out sharing that data with Google — prompting some critiques from civil libertarians:
Think current NEST users will get to decide if they want to send their info to Google? Or will only option be to opt-out by uninstalling?
— Amie Stepanovich (@astepanovich) January 13, 2014
The concern is more than simply academic. By monitoring customers' thermostat use, Google would be able to determine when a user is at home and when they're out. It would know the limits of your comfort zone, and perhaps even combine it with information gathered from your cell phone to make even deeper determinations.
"Google has made several changes to its privacy policies and its business practices," said Jacobs. "Whenever it does, the message to consumers is, 'You accept the changes or you use something else.' There's nothing really stopping the companies from changing their mind down the road and deciding to use it for advertising or something else."
A Nest spokesperson declined to comment further.