In Utah, the National Security Agency is building a $2 billion storage facility that will house and analyze all forms of electronic communication…a potential yottabyte of everyone’s (formerly) personal data. So how big is a yottabyte? CrunchGear puts it well:

http://gizmodo.com/5395095/the-nsa-to-store-a-yottabyte-of-your-phone-calls-emails-and-other-big-brothery-stuff