As Rihanna celebrated her 21st birthday in LA on February 20 with friends, Chris Brown remained in seclusion surrounded by the bodyguards he has hired to protect him. “Chris is scared,” says an insider. “Not only did he probably lose his career and his girlfriend, but he’s also fearing for his security and his life.” Chris, 19, who was arrested on February 8 for making criminal threats, has good reason to watch his back. After reports that he allegedly hurt Rihanna during an argument in a parked car, there have been calls for bans on his music as well as those who have vowed to seek revenge. “Chris is a marked man,” a music insider says. “He faces criminal charges and possible jail time, but he’s going to have to deal with Rihanna’s legion of fans and her close-knit friends in the industry.” And the leak of a police photo on February 19 of a bruised and bloodied Rihanna only made things worse. “That photo was the last straw,” the music insider says. “The threats started pouring in the moment that appeared online.”