Hasta La Motion!

In the end of the following music video: http://www.youtube.com/watch?v=E5uq03BdxyQ there is a effect at 4:54 i can’t identify, it looks like fast scrolling white graffiti going vertically. I have seen it in a few music video’s now, mostly hiphop, but i cannot find any reference to how this effect was created. My guess is a videolayer on top going at 300% speed with a high opacity. But i think it can also be done with a generator as i’ve seen it in a few video’s now. Anyone on the board that recognizes the effect, technique?