Digital cameras are now ubiquitous - it is estimated that 2.5 billion people in the world today have a digital camera. If the average person snaps 150 photos this year that would be a staggering 375 billion photos. That might sound implausible but this year people will upload over 70 billion photos to Facebook, suggesting around 20% of all photos this year will end up there. Already Facebook’s photo collection has a staggering 140 billion photos, that’s over 10,000 times larger than the Library of Congress.
Even accounting for population growth the exponential growth of photos is incredible (we take 4 times as many photos as 10 year ago). Today every party, birthday, sports game and concert is documented in rich detail. The combination of all these photos is a rich portrait of today, the possibilities of which are illustrated by a tool like “The Moment”. As photos keep growing we take a clearer and clearer snapshot of our lives and world today - in total we have now taken over 3.5 trillion photos. The kind of photos we are taking has changed drastically - analog photos have almost disappeared - but the growth of photos continues.
http://blog.1000memories.com/94-number-of-photos-ever-taken-digital-and-analog-in-shoebox