If you are using Android phone then you could have noticed recent update from Google which allowed you to "personalize your ad experience" and those settings apparently were on by default. So you have to actually do work to opt out. Here is how you can turn it off: Settings->Security&Privacy->More privacy settings->Ads->Ad privacy. It will take you to the screen in picture, go ahead and turn off all of these settings and definitely delete your advertising ID. #punkprivacy