NOW With Alex Wagner 03/04/15

Katy Perry cashes in on ‘Left Shark’

Chris Hayes, Dorian Warren, and Ana Marie Cox take on today’s top internet stories, including McDonald’s commitment to curbing antibiotic-raised chicken purchases, Katy Perry’s attempt to capitalize off of “Left Shark,” and Mayor Bill de Blasio’s decision to add Muslim holidays to the NYC school calendar. ... more Duration: {{video.duration.momentjs}}