Even though Facebook hosts the highest number of total photo uploads, Flickr has hit a major milestone themselves. Flickr now hosts over 5 billion photos. Flickr was acquired by Yahoo! in March 2005. “Flickr members upload more than 3,000 images every minute, and yesterday yeoaaronuploaded the five billionth photo. Thanks to yeoaaron and all our members for helping us reach 5 billion!” said Flickr on their company blog.