Is Marissa Mayer tracking her guests this weekend?

Unless you’re currently in a cave, you know that Google Employee #20 is getting married this weekend, right here.  Apparently the guests are being told to keep some type of ID with them at all times during the three-day festival of fun.  Maybe some type of smart card tracking device? Valleywag has all sorts of conspiracy theories.  More here.  marissa-ann-mayer