I just watched the Stones half time performance at Superbowl 40. Supposedly there was a 5 second delay on the broadcasts in case something untoward happened. But there was probably no need. The Stones are too professional at this late date to do something stupid, or for that matter to have something onstage that would screw up badly. Of course given what Keith Richards looks like these days perhaps they should have had a warning the show might disturb more sensitive viewers.