1. A method for identifying video comprising: creating, by at least one processor, a motion fingerprint for an unknown video, wherein said creating comprises: comparing a measure of luminance of pixels or blocks of pixels of a first frame of the video with a corresponding measure of luminance of pixels or blocks of pixels of a second frame of the video; identifying differences between the luminance of like pixels or blocks of pixels of the two frames; summing the identified differences to determine a measure of motion magnitude between the two frames for a given time to thereby determine an interframe motion magnitude measure; repeating said comparing, said identifying, and said summing, for a plurality of frame pairs; and using only the interframe motion magnitude measures to form the motion fingerprint, wherein the motion fingerprint comprises a plurality of the interframe motion magnitude measures as a function of time; comparing, by the at least one processor, the motion fingerprint of the unknown video with at least one motion fingerprint for at least one known video; and identifying, by the at least one processor, whether the unknown video is the same as the known video based on the step of comparing the motion fingerprint.