A friend was in town to shoot a TV advert and told me this story.
Most of the crew was local and their bread and butter is doing the local version high budget Nike/Pepsi/whatever ads featuring Ronaldinho, Beckham and the like.
Ronny they said was an utter delight to work with. All smiles, happy to pose for pictures and prepared to sign autographs until his arm fell off.
Beckham? They all had to sign a contract saying they wouldn't talk to him take his picture, ask him for a photograph or basically disturb him in anyway during the shoot. If they didn't sign, they didn't get the job.