Categorize this under “one of the worst possible PR nightmares for a Google smart speaker.” According to Artem Russakovskii at Android Police, the Google Home Mini he was reviewing was randomly and near-constantly recording sounds in his home and transmitting them to Google. The company acknowledged the problem and is issuing a software update to resolve the issue, which appears to boil down to a failure of the touch sensor on the top.
https://www.theverge.com/2017/10/10/...-recording-bug