As per Media Culpa ( kullin.net) a blog that distinctly keeps an eye on media, the photo-sharing site Flickr has hit the 5 billionth photo milestone today with the below photo, uploaded by Flickr user yeoaaron. The blogger Hans Kullin also points out that Flickr has been growing at about 1 billion photos per year.
However, Facebook also claims it was uploading over 2.5 billion photos a month in February of 2010 although it is not still confirmed, Kullin shares some of the methodology behind tracking the milestones.
Flickr provide each photo a serial number and they have officially confirmed earlier that the photo with the ID 3 billion is actually the 3 billionth photo: blog.flickr.net/en/2008/11/03/3-billion/ Date and serial number of a photo can be found via Exif data: flickr.com/photos/lenglengtan/250000000/meta/. ( Exif data is a record of the settings a camera used to take a photo or video)