Justice League of America Movie

...and I shall shed my light over dark evil. For the dark things cannot stand the light, The light of the Green Lantern!

Hal Jordan was a test pilot who was given a power ring by a dying alien, Abin Sur, and who became a member of the Green Lantern Corps, an interstellar organization of police overseen by the Guardians of the Universe. The Corps' rings were powerless against anything colored yellow, due to a necessary impurity in the ring. Each Green Lantern possesses a power ring that gives the user great control over the physical world as long as the wielder has sufficient willpower and strength to wield it. Source