Four years ago, Twitter bought Vine, an app that let users upload and browse looping six-second video clips. While a community of people who elevated repeating video clips to an art form grew around the site, which hadn’t actually opened yet when Twitter bought it, Instagram and Snapchat also grew since then as places to share short videos. Now, on the same day that it cut 9% of its staff, Twitter announced that it’s shutting down Vine. [More]