A masked assailant threw acid at the artistic director of Russia's Bolshoi Theater ballet troupe, an attack that Bolshoi representatives said may cause him to lose his eyesight and appeared to be linked to power struggles at the famed ballet company. “What happened with Sergei Filin was not accidental,” Ratmansky, now an artist-in-residence at the American Ballet Theater, posted on his Facebook page. “The Bolshoi has many ills. It's a disgusting cesspool, of those developing friendships with the artists, the speculators and scalpers, the half-crazy fans, ready to bite the throats of the rivals of their favorites, the cynical hackers,...