It's for ALS research (also known as Lou Gehrig's disease). People are challenged to either donate to the cause (the main point is awareness since it's not one of the more commonly known disease (it's one that paralyzes the body but the mind's active-scientist Stephen Hawkings is one of the more well known victims) or donate AND videotape themselves within 24 hours of being challenged of being ice bucketed since that's the same feeling of those who have the disease feel daily. Most people go to the lengths to explain that and again for a good cause it's a good thing. Hope that clears that up and yes the Old Spice guy (Terry Crews too when he's not around to do the ads) are also pretty funny comedians.