Forget flesh-eating zombies and Lord Voldemort, celebrities seen in Harry Potter movies and the Walking Dead TV show are now going up against some real power. In a short film released February 18, some big film stars promote a financial transaction tax, which Wall Street lobbyists and their European counterparts fiercely oppose. The three-minute film’s director is David Yates, who made the last four Harry Potter movies. Actors include: Andrew Lincoln (star zombie-fighter on the hit AMC TV show “The Walking Deadâ€), Bill Nighy (“The Best Exotic Marigold Hotel†and “Love, Actuallyâ€), Javier Cámara (star of Pedro Almodóvar films “Talk to Her†and “Bad Educationâ€), Clémence Poésy (“Harry Potterâ€), and Heike Makatsch (“Love, Actuallyâ€).