Oneof the biggestpitfalls came late last year, whenFacebookannounced an advertising program called Beacon that broadcast news of users'onlinepurchasestotheirfriends.
One of Benedict XVI's last acts as pope, according to Vatican Radio, was to authorize the broadcast of video of the shroud from Turin Cathedral, where the mysterious Christian relic is kept, out of sight, in a bulletproof, climate-controlled glass case.