Once in a great while, a Steelers opponent will try to use Polamalu's hair against him in a game (as Kansas City Chiefs running back Larry Johnson(notes) did in 2006 as Polamalu returned an interception), and it's quite possible that the concern over such matters was the catalyst needed by Head & Shoulders to insure Polamalu's hair with Lloyd's of London for $1 million, which was reported by the Associated Press.
Then again, it could be a publicity stunt. Lloyd's is famous for unusual policies that can be turned into media gold; the company has insured Tina Turner's legs, Keith Richards' fingers, the legs of noted Riverdance ponce Michael Flatley, the bodies of several professional wrestlers (including Ric Flair -- Woo!), Jimmy Durante's nose, and Celine Dion's vocal cords (they're also talking with Virgin Galactic about insuring space travel, if that ever gets off the ground). Polamalu's hair isn't going anywhere, but it's a nice press haul for company and endorsee.