http://www.techradar.com/news/google-disables-the-mini-speakers-top-button-to-fix-spying-bug

Yesterday news broke that a Google Home Mini speaker had gone rogue and started recording everything that was being said around it – not the way Google's smart speakers are intended to work, and not the best way to earn the trust of users.

It seems the issue only affected a select number of devices, but now Google has turned off the ability to tap the top of any Google Home Mini to issue a voice command, which should be enough to stop the bug from rearing its ugly head. The "OK Google" command can still be used to 'wake up' the speaker.