Did you opt to let Android "help you get a better user experience" when you setup your phone ?
I have an instinctive aversion to sharing my life with online media and gadgets and huge corporations that only want to exploit me.
The recent scandals only shows us that the world has been naive when thinking that these corporations are "nice".
I have noticed recently if I am on a vendors shopping site and on that site search for "tool backpack", then suddenly I get advertisments for tool backpacks on all the other websites that I visit. I dont know if it is the browser that hijacks my search input and send it to google or someone else (I use Firefox), or if the websites just share the users searches with google . I dont like that they share my possibly private seach phrases with a 3rd party witout my consent.
Call me old-fashioned, or a contrarian old man, but I dont use Facebook or Twitter or any other such media.
And I would never install a microphone in my own home to record what I say and send it to a remote server out of my control.