After Google told users its Nest Secure system’s upgrade would let it be used as another Google Assistant speaker, people were confused—because they didn’t know Nest had a microphone, to begin with. Now, Google says the built-in Nest microphone was never supposed to be a secret.

Nest Secure, home security and alarm system, originally launched in 2017. However, nothing about the product disclosed its microphone. A spokesperson told Business Insider that the microphone “should have been listed in the tech specs. That was an error on our part.”

There’s been controversy around various home speakers and their recordings before. Amazon’s Alexa once sent 1,700 hours of recordings to the wrong person. Plus in 2017, Google admitted a flaw in their mini speaker let it secretly record conversations without users knowing.

In its statement, Google did say, “The microphone has never been on, and is only activated when users specifically enable the option.”

Still, it’s reminiscent of a 2010 incident where Google said its Street View cars “accidentally” collected personal data through WiFi networks. As both the Street View cars and previous speaker issues show, devices can collect information without their users or even the company that designed them knowing.

If you want to know why Nest Secure even has a microphone, security systems often use them to provide features that rely on sound sensing. Google said, “We included the mic on the device so that we can potentially offer additional features to our users in the future, such as the ability to detect broken glass.”

Nest Secure’s product page has been updated to mention the microphone.