Youtube keeps a history of videos you’ve watched and search history. If you want to disable this, sign into Youtube, then go http://www.youtube.com/my_search_history.
- You can clear your search history, and click “Pause search history”. This will prevent it from saving search results in the future.
- On the same page, click the History tab on the left. You can clear your viewing history, and pause it by clicking the “Pause Viewing History” button.
You can also clear your “Likes” and “Favorites” from this page.