Shia LaBeouf is an American actor and director. While he has appeared in various movies and TV shows, he is most known among the Internet for his motivational speech, famous for its intensity and the line "Just do it!", which has been widely linked to Nike, whose slogan is the same phrase.
Shia's motivational speech is now popular across the web, and appears in many YouTube videos, like YouTube Poops. Because the motivational speech was filmed with a green screen, various people have replaced the green screen with different backgrounds.