“From the beginning of recorded time until 2003, we created 5 billion gigabytes of data. In 2011 the same amount was created every 2 days. By 2013 that time will shrink to 10 minutes.”
Random research shows that a huge percentage of that is UofN staff and students posting and re-posting photos and videos . . .
More at HumanFaceOfBigData.com, seriously, it is an amazing book.