Facebook made the thumb up and down icons and graphics synonymous with liking or disliking (not liking) something. Since, it's because a standard for apps and websites to use those visuals to prompt their visitors to show their approval (or disapproval) of a thing. For example, rating a movie, photo or video. All the thumbs up and thumbs down icons on this page can be used for your project. Enjoy.
All the icons and illustrations above can be used for both Personal & Commercial purposes.