Those are pretty good for a wake up call on somebody, and theres tons more out there on the net. but they are considred dangerous believe it or not - they have caused people to go into cardiac arrest (heart-attack) and go into siezures. to the un-assuming they can be deadly! a few websites with them have a "disclaimer" that upon reading and understanding it before you view it, they cannot be held acountable for any health risks that the viewer might encounter...