Now, thanks to a whistleblower, we find out that Google is doing it too via their Google Home smart speakers, despite repeatedly claiming that they don't eavesdrop, according to Dutch broadcaster VRT - which notes that the recordings are happening whether or not the speakers are activated. 

VRT NWS was able to listen to more than a thousand excerpts recorded via Google Assistant. In these recordings we could clearly hear addresses and other sensitive information. This made it easy for us to find the people involved and confront them with the audio recordings. -VRT

"This is undeniably my own voice," said one man tracked down by VRT based on recordings obtained by the outlet. Another couple from Waasmunster, Belgium said they immediately recognized the voices of their son and grandchild. The recordings include conversations and quarrels between people, confidential business calls, conversations with children and 'bedroom activities.'