Kim Kardashian and sisters Kourtney and Khloe blocking Blac Chyna from using their name is 'standard protocol'

LOS ANGELES, CA - FEBRUARY 20: Model Blac Chyna attends the press preview at Tyga's "Last Kings" flagship store on February 20, 2014 in Los Angeles, California. (Photo by Paul Archuleta/FilmMagic) [Getty]But the model, who gave birth to their first child last month, was left “heartbroken” after her future sisters-in-law, Kourtney, Khloe and Kim Kardashian, reportedly tried to block her from trademarking her new name.According to reports, Kris Jenner’s daughters moved to block