Not to be outdone by troubled music producer Kanye West and his odd collection of face masks, pop idol Justin Bieber wore a trendy gas mask during a stop at the appropriate named Acne Studios in London today. Celebrity fashion blog Upscale Hype suggests that Kanye is starting a new fashion trend with his face masks. West was seen wearing a Maison Martin Margiela crystal mask in Atlantic City, NJ, and a red ski mask in Paris, France last week. And rapper A$AP Rocky donned a black ski mask at the Y-3 Fall/Winter 2013 show during New York Fashion Week. It remains to be seen if the face mask fad catches on with Kanye's fans.