To keep YouTube from saving your searches from this moment on, tap the "Pause search history" button--and yes, you can always turn it back on later.
To see the history of YouTube videos you've actually played: From your YouTube search history, tap the Watch History button near the top of the screen to switch to a list of your played YouTube videos. From here, you can view, delete, or pause your history of watched YouTube videos, just as you did with your YouTube search history.
Here's perhaps the creepiest way in which Android keeps track of what you're doing--or, in this case, where you've been.
If you give Google the go-ahead, Android can keep tabs on the location of your various devices, periodically pinging Google's servers with the position of your Android phones and tablets--even when you're not actively using your devices.
You can even pull up a map showing where (for example) your Android phone's been on any given day.
So, what's the point of all this? According to Google, your "location history" helps apps like Google Now to be more prescient when it comes to, say, letting you know how long your commute is going to be, or which restaurants are on the way home, or what's playing at a nearby movie theater.
To remove any of this history, go to the Account Activity screen in the Google Settings app. Tap Google Location History, then uncheck any or all of the devices whose location you don't want to be shared. You can also tap Delete Location History button to wipe your past location history clean.
To see the map of where your various Android devices have been, tap the three-dot menu at the top of the Location History screen, then tap View/Manage.
Note: Just because you've paused your Google web history or deleted your location history doesn't mean no one's monitoring your Android activity. All your web site visits are duly recorded by your ISP, for example, while you wireless carrier can track "pings" from your Android phone on nearby cell towers.
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