https://techcrunch.com/2017/10/11/citing-a-few-malfunctions-google-nukes-touch-function-from-home-mini/

Google is permanently axing all “top touch” functionality from its new Home Mini device after a nasty bug was documented yesterday that essentially recorded everything around the gadget and sent it to Google. These things happen! Either the company couldn’t be sure it could fix it or it couldn’t be sure people would trust that it did — so they made the choice to nuke it from orbit.

The bug, first reported by Android Police, was apparently a hardware issue that caused the touch sensor on the top of the device to register touches pretty much constantly. Touching the device is — well, was — an alternative to saying “OK Google,” waking the device up to listen to your commands. All of your voice interactions, of course, are sent to Google and kept in your account history. You can turn that handy “feature” off here, by the way.