The following video is impressive.
It shows the effect of hundreds of green laser pointers on an Egyptian chopper (possibly an Mi-8/17 Hip) during the anti-Morsi protests in Tahrir Square, Cairo, Egypt on Jun. 30, 2013.
The lasers make the chopper fuselage appear green and can be seen hitting the blades well. Quite impressive if seen from the ground, much disturbing if observed from the cockpit!