Wall Street Journal: Snapchat CEO Evan Spiegel is on a mission to explain why his company is relevant for people today. Deleting all of his tweets seems to be part of the plan. In a new video titled ‘What Is Snapchat?’ uploaded to YouTube, Spiegel said social media used to be a place where photos of a person were viewed as a collection, in a world where “identity is everything I have ever done.” But instant expression — like on his ephemeral messaging service Snapchat — has changed this, he said, because “instant expression says my identity is who I am right now.” Spiegel deleted all the tweets on his Twitter account, in what could be a move to establish himself as more of a thought leader in the industry.