This week’s tech news was all about social media. We talk to Xeni Jardin about “The End of Twitter,” an article in The New Yorker magazine last week that proclaimed the death of Twitter was upon us. Social media users weren’t too happy about that. We also discuss Instagram’s first scripted series, a college calling for a major fitness crackdown involving Fitbit, and the new Whitney Museum exhibit “Laura Poitras: Astro Noise.”