Loved this image from a NYTimes article on fans of “Gossip Girl.” The teens were hanging outside of the show’s filming and displaying “proof” of their experiences — pictures with the actors.

When we do diary studies at YouTube to understand mobile video usage, “proof” often comes up as an important use case for mobile video. People want to prove they saw a celebrity, dated a certain guy, were at a specific party, finished a race, made it to the top of the mountain, etc.