i feel that it is my responsibility, as an adult, to bring some sanity to this discussion.....there is no frickin way anyone would ever be damaged by, at most, 20,000 make up mirrors (much less aluminum foil which is probably about 10% as reflective), with no coordinated movement, from as far as the third deck of kyle down to the field. even if we were able to convince one of the players to stand still and let everyone try their best to shine their mirror on him, do you think it would work? do you think anyone 50 yards+ away from the "target" would be able to distinguish where his ray of reflected light was directed?
don't get me wrong, i love the idea, but i encourage the students to go to the field and experiment before you spread the word. i think you'll find that even pie pans are simply going to look like silver object from the field, vs. causing any visual disturbance.
no, if you want to damage someone i suggest finding a few HUGE lenses and building something similar to a telescope (in reverse), climb to the top of the press box, and focus it such that the light converges on the crotch of mike leach. similar to a magnifying glass on ants.