They can deny this all they want but the evidence is clear. There was a story recently about an Alexa device "accidentally" recording a family's conversations. The reason this came out was because some malfunction or error somewhere along the way caused it to send the recording to one of the family's contacts instead of wherever it was supposed to go. I can't remember which news site covered this originally but it was also mentioned on a recent episode of the podcast, Deep Fat Fried.