Block Ads on Youtube using Ghostery ADDON
Ghostery sees the "invisible" web, detecting trackers, web bugs, pixels, and beacons placed on web pages by Facebook, Google, and thousands of other companies interested in your activity.
Ghostery allows you to block scripts, images, objects and framed documents from companies that you don't trust.
Ghostery also includes the optional, opt-in feature called Ghostrank, which sends Ghostery servers anonymous information about the trackers you encounter and where you encounter them. This allows us to create a more comprehensive list of detectable items, and helps us create a more transparent behavioral advertising ecosystem.
For Chrome
https://chrome.google.com/webstore/detail/ghostery/mlomiejdfkolichcflejclcbmpeaniij?utm_source=chrome-ntp-icon
For Opera
https://addons.opera.com/en/extensions/details/ghostery/?display=en#
For Firefox
https://addons.mozilla.org/en-us/firefox/addon/ghostery/